I would be lying if I said I didn't miss the days where I used to be carefree about what I ate. What I DON'T miss is the horrible feelings that came after eating large amounts of food. I didn't enjoy feeling bloated, lethargic and sick.
That epiphany you just had is very important! It's a big step toward your ultimate goal
However, there are actually very few people who can eat whatever they want and not gain weight. The majority of those folks who we see seemingly eating everything in sight really aren't able to eat massive amounts of food without consequence. Unless you straight up ask them you don't know what they've eaten that day until they've gotten to the meal you see them eating.
I always thought my fiancee was like that since he's relatively thin without much effort on his part. While I'm sure good genetics come into play, it wasn't until I really listened to him that I realized he wasn't eating everything in sight, he was practicing portion control without realizing.
He's 6'3" so he can already eat more than the average person without gaining weight, but I came to realize that he wasn't one of those "eat whatever" people when he came over and we had pizza one day. He ate four slices but told me he was starving because he hadn't eaten all day.
So I thought about it and realized that this occurred more often than not.
Depending on the size of the pizza, it can vary in the calories, but I think an average size slice from a New York Pizzera probably doesn't come out to more than 350 calories (and that's a higher estimate... looking up the info puts a lot of slices at under 300) If he had four slices, that's 1400 calories. That's LESS than he should be eating to maintain his healthy weight. Not the most nutritious meal out there, but calorie wise he's still under. Even if we really put the estimate at the high end of 500 calories a slice, he would be eating 2000 calories. Probably still on the low side for a man his size.
In exploring the eating habits of some of my friends who are like my fiancee, I realized that they are much in the same. They don't generally eat the healthiest things, but they eat the right amount without even realizing it. I wonder if it was their upbringing or if they're genetically coded to better decide what a proper portion is (or perhaps a bit of both).