Started playing at 15, I’d been in “sortof” bands with mates since I was 16 , the type where you say you’re a band but have never actually done anything other than make a racket with no-one playing anything remotely like the others who are also doing the same.
At just turned 21 I bought my first decent bass, a Yamaha BB1100s, about a month later joined a proper established originals gigging band. So I suppose I must have known in the back of my mind that I’d outgrown the sortofs and was ready to apply myself better. Within 3 months I was gigging all over the country.