Selfies

Yesterday someone told me that, someday in the future, I'll regret not taking pictures of myself.

Honestly, I can't see why. Though it's probably true.

That doesn't mean I'm gonna start posting selfies everywhere, every damn day. However, I'll leave this -a picture- as a proof.
If someone or even myself wants to remember how what I looked like at eighteen, I want it to be with all and my freckles and dark circles under my eyes caused by all those restless nights of studying, and worrying about a future that, just maybe, turned out better than I think now ("turned out better than I think now" might work better as "might turn out better than I think it will right now," depending on what you mean). I want to see my flaws, the things that made me insecure back then, and I want to see the pink color on my cheeks, part of the youth that will never come back.

I want it to be the realest it can be. ("I want it to be as real as it can be" would be how this would usually be written. "Realest" isn't really a word, but it is sometimes used as slang in rap/among young people, so in context actually "realest" almost would work.)

Great job! The small suggestions I made to me sound slightly more native, but what you wrote is completely understandable. Poetic, even.