It's easy to be wise with hindsight, but after mulling this over for a bit, I'm pretty sure I'd have gone hell-for-leather for a pro career if I'd started as a carefree teenager instead of (cough, cough) years later. I absolutely love almost all* aspects of live performance - dance, drama and music - and I think I might have done OK.
Even if I hadn't, at least I'd have tried.
*Midnight load-outs, stroppy/drunk punters, lugging heavy gear about, hours on the road, crap hotels, colleagues with hygiene deficiencies and junk food from motorway service stations excepted, natch. But you have to take the rough with the smooth.