Believe it or not, some of us never planned to play live, be it Donington, our local or a jam session in a friend's living room, when we picked up a bass for the first time.
Some of us love working out basslines by ear - while at the same time discovering and analysing the structure of the song, and opening it like a little box of fascinating tricks. Once we've done that, we play along to it until we get it right/can't get it wrong, then punch the air and go "Yess!".
Repeat ad infinitum, or for as long as fingers and ears keep functioning