When I stopped binge drinking about ten years ago I had just one bass, my beloved ESP jazz. I started having money for the first time in my life so I bought a Ric4003 fireglo. I enjoyed that a lot, very different beast to the ESP. Then I was playing in a proggy-metal band where I had a lot of room to fill so I bought an Ibanez SR3006 and it went from there. I enjoyed having to re-learn and adapt my technique to a six string format. I've got 10 basses now, all fairly different, though quite a few have passed through the door in the meantime, including the Ric and the SR. I enjoy having different basses for different sounds or different moods. Yes, I could abviously get by with just the ESP but I love playing bass, I don't feel guilty about having multiple instruments, I don't need to justify to myself or anyone else, the bills get paid so why not? At the moment, the only basses I'm really GASsing for are a Yamaha BB2024X and a four string Wal MkII, but if something interesting appears at the right price, you never know.