Hi Alper,
I'm 32 years old and I am proud that to say I peace of my age because 'age' is just number you can't change. it is essantial thing ''you're how do you fell it ''.Maybe you're 19 years old but you're feeling 30 years old cuz you have hard life conditions, you have too much responsibilties, or stress etc..

I think , there is no ''the best age'' every age can be beautiful it is all about us, how to live our lifes but sometimes I really miss my childhood. :D

Probably, 25. At this age you think you know everything about life,  but in the reality you know nothing. 

The strong point of it is  you don't know, that you don't know. It's like a new driver after half a year  behind the wheel. He thinks he have already mastered driving unless it comes to some sticky situation. 

Anyway, this unawareness makes your life easier and more enjoyable.