It can be learned
Aggressive Playing Style can be learned, with a lot of practice though. If you want to be aggressive, be prepared to lose many more hands in cash and tournaments if you are trying to learn this style. Aggressive play is best done by naturally aggressive players for they are used to it and it is a part of their game. Trying to adapt other game styles to your own, can be quite difficult, but not impossible, but can be a long road before you see any benefits to this.