Yeah dude just shake it off... there is no need beating yourself up over one girl. Think of all the sexy surfer girls out there and just straight sexy girls out there... if things were truely meant to be between you two then in the end sh*t will work out between you two... I suggest keeping things on the friend basis with her though just incase... but in the meantime experience the world and all the sexy girls it has to offer
On to the next one my friend! The best thing you can do is not pay any attention to the "ex" and go find the next one. The last thing you want to do is let her know that it bothers you, like someone already said; it will empower her.
All girls are about the chase so whether you want her back or you just want to "get back" at her, you need to go find another girl. The other girl could be a pawn, used only for getting your Ex back. On the other hand, (and this is my favorite) make your Ex feel like **** and rub every girl you bang in her face!