I'm not even a pretty good player.

Kevin:
 
First of all, Flax is being too kind.  I ain't the greatest, but I have FUN which, in the great scheme of things, is really what it's all about.  All you gotta do is know a few chords - (wait, you're a bass player ...  heck you don't even need to know a few chords ... just a scale or two) - and keep your ears and mind open.  
 
I used to be a brutal self-critic when it came to my playing.  I thought I only knew some easy stuff and I was just fooling people who told me they liked my playing.  Even when I started to feel like I was getting decent, I'd hear a player that would just blow me away and make me feel that I was BSing myself and I really stunk.  Over the years, though, I began to notice that the players who blew me away were getting better and better!  I also noticed that when I heard someone play something that seemed hard, and then I learned it, my perception was that it was really easy to play.  
 
Then it dawned on me like a bolt from the heaven's!  My personal definition of easy vs. hard when it came to playing was this: if I knew how to do it, it was easy - if I didn't know how to do it, it was hard.  (I preach this to my 10 year old - with a little effort, hard things become easy things).  With such a definition, I would never be able to play hard pieces.  These days I don't really worry about it.  I certainly ain't Jerry, Carlos, Eric, or Robbie (Robertson - underrated IMHO), but I have a blast playing with other people and I (usually) don't embarass myself.
 
Unless there's a stadium full of people who each paid to see YOU, the only thing that matters is having a good time.  In an interview long ago, Jerry was asked why the Dead don't use stage props, fog machines, etc.  He replied that the best show possible was a bunch of musicians on stage thoroughly enjoying themselves.  That's the GREAT TRUTH!
 
I'd love to get a jam together next time I'm in NY.
 
Bill, tgo

fun is the key bill.....