I couldn't click any of the answers. I've been playing in two more-or-less bands for about 2-1/2 years. Neither one is together enough to get work in the public eye. Nonetheless, this is how I have learned to play: I practiced by myself for about a year, and then started playing with other people. Having no experience, this has been extremely important to me. It has forced me to learn theory, technique, and many specific songs. I can echo many of the complaints I've read here, but it does no good. Whatever the rough spots, this is how I've learned. I hope that some day I can get a chance to play in a "real" band that has an audience, and maybe even get paid. That would be really cool. In the meantime, I just try to get better.
Playing by myself is what I've done with guitar, fiddle, piano, and lastly, bass, pretty much all my life. It's pretty limited. Every time I've had a chance to play music with other people it has seemed like the most fun I have ever had (at this point it's obligatory to say "with my clothes on," but I'm pretty old and that isn't necessarily true any more).