I smiled when I read fcSR5k5's post about not playing for 3 years. After playing through of much of high school, I too stopped not long after going away to college. I literally didn't touch a bass for 29 years, until I started playing again in March 2003. I couldn't remember a thing (including what notes to tune the strings to!), but once I started playing with other people (including a drummer and a guitarist), it started coming back. Which was good, since I was scheduled for a church gig in 5 weeks from the day I picked up my old equipment. Now I'm playing all the time.
My suggestion is to find, if possible, some non-judgemental musician friends (especially a drummer) to jam with. Also, play along with some CDs. And just play and play as much as you can. I probably am playing 10-15 hr/week along with people and CDs (not counting my regular church gig and practice). Don't worry how good you are initially. If you play a lot and enjoy yourself, you'll get better real fast. I was amazed how quickly stuff came back. I know there are still some positions, etc. that I don't remember, and my fingers are older and stiffer than they were, but I can still play a mean bassline when the eyes roll back in my head and sweat starts pouring down my brow!
Now I'm going back and working on some theory.
Have fun! That's the point, isn't it?
Gordon