My first instrument was piano (still play keys in the studio).
I got my first bass (a cheap one, which I still own - never had a name on the headstock) when I was 17.
I learned playing bass by sitting on the side of my bed playing along with my television (commercials, etc). Back in 1977, I had no VCR so being unable to pause or rewind anything, I had to learn to catch things on the fly!
My influences have always been guitarists (Eddie Van Halen, David Gilmour, Alan Holdsworth, Yngwie Malmsteen and more).
Re: my influences, I guess my time as a keyboard player, playing bass with my left hand and chords with my right, I kind of carried that thinking (left hand supporting right hand) over to bass and guitar.
Although I started playing bass in 1977, I didn't actually start taking it seriously until someone gave me a copy of Van Halen's first album.
Listening to Eddie's playing, which I had already been reading about for quite a while, made me take a close look at where I was as a bassist.
These days if I'm not gigging or in the studio, you can usually find me at an open jam somewhere.
Jam's are a great way to network with other musicians and you never know who'll show up on stage.
One of the reasons I love attending open jams is I like being in situations where I don't know what to expect musically or who to expect it from!