Figure out exactly what it is i want to do after i graduate

Okay so this is buggin me lately. Im nearing the end of my time at University, a time which is rapidly decreasing yet i still have no idea what it is i want to pursue in my time after uni? I really have no clue. I mean, when your 5 its simple, you want to be an astronaut, a wrestler or some big time rocker or something. But when you get older its much more difficult…i have to decide to do something for the rest of my life but what…