You can be anything you want to be, provided you can figure out what you want to be.
If you just can't figure it out, you can probably find someone to tell you what to be.
The key to success, therefore, is continuing to want It. And don't change what It is before you get It. Then you can move on to a new goal.
I say this as one who has no room to talk; a stark example of the pit that yawns to swallow the restless, inquiring mind.