Man has taken a selfie every day for 15 years. His transformation is fascinating to watch.

One of the fun things about traveling to different countries is that you not only get to learn about other cultures, but you also learn some things about your own. Americans who travel abroad often learn that people around the world appreciate them for being open, friendly, and good at spreading hope and optimism.

On the other hand, people in other countries can often tell when an American is coming from a mile away because they speak loudly, whether indoors or outdoors. Americans also have a very peculiar body language and are known to lean on things when they have to stand for an extended period.

A Reddit user posed a question in the AskReddit subforum to learn more about how Americans stand out abroad: What's an "obvious" sign that someone is American? The post received more than 35,000 responses, with an overwhelming number of commenters noting that Americans are all smiles and love to make small talk, something most people appreciate.

According to Redditors, here are 15 "obvious" signs that someone is American:

1. They have a unique confidence

"An Italian told me that Americans walk confidently in the wrong direction."

"Been taught to walk fast, and look worried.. People think you know what you're doing."

2. They're friendly

"I worked as a cashier in a tourist place in Paris, I always recognised Americans because they were kinda friendly to me and they always left tips."

"I guess there are worse things than friendly and generous."

3. Time = distance

"If someone asks how far away something is, an American will tell how you long it takes to get there as opposed to a physical distance."

"It actually pisses off some Americans to give a distance in miles, unless they're calculating gas mileage. In some places, you have to give with and without traffic options. I think it's more valuable info in time than in distance."

4. Grinning at strangers

"The gentle grins you give to strangers if you make eye contact with them as you pass by, at least in the Midwest. was not well received in Germany."

"I dated a European man here in the US. When we walked together, every time I made eye contact with someone on our path I would smile at them, and they would always smile back. Boyfriend was so confused at all these strangers smiling at me. Kept asking if I knew all these people. It was hilarious."

5. They like personal space

"How much personal space they give themselves. Americans like at LEAST an arm's length."

"We're conditioned to fill spaces evenly. I noticed when i worked delivery, spending lots of quality time on elevators that for every new person that enters, everybody shuffles to even things out. Similar thing plays out in social gatherings and bars. Not sure if that's universal or not, but I find it interesting. I think the size of our personal bubbles is because our spaces are generally much larger because we've got the space (heh) to build bigger buildings, sidewalks, roads etc. Might also explain why we're louder. Used to filling larger spaces with volume."

Body language expert Joe Navarro says that among Americans, the social zone for acquaintances and casual interactions is four to 12 feet, while family and close friends stand 1.5 to four feet apart. The intimate zone, for those closest to us, ranges from the skin to about 18 inches.

6. They lean

"According to the CIA, when training to be a spy, you have to unlearn how to lean. Americans tend to lean on things when standing still."

All of this is true, according to Jonna Mendez, the former chief of disguise at the CIA, who has shared some of her tips and tricks for making Americans seem more European. "So we would de-Americanize you," Mendez told NPR. "They think that we are slouchy, a little sloppy. And they think that they can almost see that in our demeanor on the street because they stand up straight. They don't lean on things."

7. They don't have an indoor voice

"I've lived in America for 25 years, and it still irritates me that instead of lowering their voices in restaurants so everyone can hear, Americans just scream over each other and make their restaurants as loud as clubs."

"For some reason, my otherwise smart and wonderful American friends will speak in the same volume, diction, and speed regardless of any outside factor unless specifically asked."

8. Dessert for breakfast

"In my homestay in London, I was told that I was 'so American' for enjoying a piece of cake for breakfast (not frosted cake, but like a nuts and dried fruit spiced coffeecake kind of thing). Apparently, that's exclusively for like a 4 pm snack, and breakfast is more of a savory meal."

"A lot of American breakfast items in my mind are desserts (pancakes, muffins, waffles, etc.). It doesn't mean I won't eat them, but it's kinda weird to do so."

9. They wear their clothes differently

"A British man once told me he knew I was American because I was wearing a baseball cap backwards."

"An Italian told me they could tell I was American because I wore my sunglasses on the top of my head when I wasn't using them."

10. Exposed soles

"While visiting Turkey, I was told that I looked American because I was sitting with one leg across the other, and the bottom of my shoe was exposed. Apparently, it's rude idk."

"In a lot of places outside of the US, showing the bottom of your shoe is rude."

11. Tactical gear

"Tactical sunglasses."

"I'm in the US, and virtually anything marketed towards men has the word 'tactical' in front of it."

12. They love small talk

"I'm from California (though a smallish town), and we wave to neighbors on our road, even if we haven't met, and start conversations in the grocery line with people if the opportunity presents itself. Also, smiling and saying hello to someone you happen to walk by and make eye contact with is quite normal. We are a social species, it would be so weird not to be friendly, even to strangers, for me, and I'm not even that social of a person."

"What really gets me to it is not that Americans do small talk constantly, but the fact that they are so good and fast at it. I mean, I say 'yeah, it's hot,' and they reply with some interesting fact or make a connection to their hometown. I feel less of myself after this. They must have some small talk class in school or some sh*t."

13. They like to point

"I've always observed my US friends like to point at stuff while walking and say what it is…. We were out walking around Amsterdam recently and they were like 'hey look it's a smoke shop'…. 'Oh look a sex shop'…. 'Oh hey, it's a prostitute' …. 'Look at the canal'…. 'Wow it's another prostitute'….. 'another canal' etc etc. It was like watching Netflix with Audio Descriptions turned on."

"You know that little voice inside your head, your internal monologue? Americans seem to monologue their thoughts."

14. Optimism and enthusiasm

"Dunno in all context, but Americans in Europe stand out with their ceaseless optimism and enthusiasm."

"I'm reminded a lot of Ted Lasso. Everyone I know (all Americans) loves the show. I wonder what kind of European fan base it has."

"Americans are so positive and have such a thirst for life. It sickens me."

15. They eat while walking

"When I lived in Europe, people said only Americans eat while walking. I'd be eating a bagel or something on the way to work or class, and multiple people asked if I was American lol."

"Jay Leno said on Top Gear, I think it was, that Americans are also the only people who eat while driving. I don't do this, but I constantly see people who do, haha, especially in LA, where people spend a lot of time in their cars."