For example, when people say they want to write a book or be a novelist, what they really mean is, they want to have written a book and been a writer. They're looking at the finished product. This is likely true of most people who want to do X, because they see it as a solution to their current situation.
The better thing is just sit down and write stuff. Poems, diaries, letters, very short stories and vignettes. See where it takes you.
The professor thing made me laugh, because some people like helping others grow and learn and blossom, despite all the day to day stuff. That was my step father's motivation for it. He found he enjoyed it.
There is value in just throwing yourself into something and seeing if you enjoy it. For example, I have a friend who started brewing his own beer. He loved everything about it, and enjoyed it. He connected with other home brewers, and gradually he ended up becoming a master brewer. He didn't start with the end in mind, he threw himself into what he was doing and carried on because he enjoyed it. Funnily enough, another friend started roasting his own coffee beans because he liked drinking coffee, and today he sells his own beans, and has just opened his own coffee shop. He carried on doing it, because he enjoyed it.
I've always liked Tim Minchen's advice on this: "And so I advocate passionate dedication to the pursuit of short-term goals. Be micro-ambitious. Put your head down and work with pride on whatever is in front of you… you never know where you might end up. Just be aware that the next worthy pursuit will probably appear in your periphery. Which is why you should be careful of long-term dreams. If you focus too far in front of you, you won’t see the shiny thing out the corner of your eye."