When you've been traveling so much that the airport starts to look like a fancy-er train station and the airplane an unusual bus. I remember being a little kid and going to the airport would mean putting something nice on, now we just get comfortable (another proof we are getting smarter after all haha). 

It still sounds better than it is, we commonly get jealous of someone who's always jumping from city to city. But we forget that most times there's not much time (or energy) to go to the best spots and the coffee by the hotel means outside brunch.
It's also often forgotten that someone that takes an airplane 4 times a month or more to visit the same place, it gets exhausting. I don't know you but I am unable to work on an airplane. It bothers me a lot because it would be perfect to get a few things done, but I literally can't think.
Visiting a city where you have many friends, means you need to see everyone, it ends up beeing more pleasant but you end up super exhausted. I usually don't mind because I don't have a 9 to 5 job where I need to look decently awake on a Monday morning, but since it is the most common, it's good to have that in mind. 
I feel that some of the most obvious are also easily forgotten - people who travel the most often get the best deals - we are not going first class or having the entertainment of shopping before the flight. We are usually running ridiculously late or trying to grab something to eat.
We are the best packers though, after months of traveling I managed to pack a sports bag for a week away use everything and miss absolutely nothing. But considering I've been traveling for 5 years... I mean at the beginning traveling without hold luggage for a week was pretty much impossible in my mind. But I guess traveling itself turned me into someone more practical. Sliding through the security line and not having to call an Uber to carry luggage to a walking distance hotel. I still need to look at my timings though, almost lost a delayed flight in Nice.

About the look, got to love a nice trench style drape coat. I am wearing mine over my Airplane Mode t-shirt (by the way if you haven't seen my new t-shirt line go have a look, I have more designs coming up this month, yay!). For bottoms black Adidas leggings and my go-to white low cut converse. Most of the times I put on a total black midseason look with a colored jacket. Last time I traveled, had a different pair of sunglasses, a different type of black leggings, this same t-shirt (but the re-design) and a pink denim jacket. What's more interesting is that I usually only dress like that to the airport, so next time you see me on a total black look with converse and sunglasses and a random jacket, you know where I am going! haha