Is it necessary to live one's life by planning out every last little aspect and detail, creating a plan B, C and D for every possible contingency, and sticking to the plan right down to the tiniest little facet? Think of writing a story as a bit like life. Some people live spontaneously, in the moment, and seem to do just fine... for others it takes careful planning, while for others still it's a mixture of both. Don't ask if it's a good idea or not. Just jump out and write! It's not like you'll be risking anything, and you'll get an answer soon enough -- when your attempt peters out into nothing more than a stillborn attempt at a story, or -- conversely -- suddenly takes on a life of its own.
Planning distracts me. I like to free think when I write. I scribble down general ideas and possible additions, but I don't actually plan out anything with outlines or the like. It's too structured for my...rather free spirit... ;D
When I come up with short stories, I'll generally think of a single line and start writing. I'm as surprised as the potential reader by the time the thing's through.
most good writers write 'by the seat of their pants'... some need to plan first... there's no right or wrong, wise or foolish... just what works...
I'm not sure Wisdom has anything to do with it, to be frank. I've written long and elaborate stories without any planning but as f late I have found I crave a little more structure, so I like to outline.