Of course that was scary, and you were right to check it out. But I've had that happen, and your medical advice is almost certainly right -- you don't need to worry (at least about the arm issue).
It may not even be "nerve issues," just circulation getting cut off temporarily. I am quite prone to my feet and legs falling asleep. And once, when I was using a sleeping bag during a Model U.N. field trip, my left arm fell asleep when it was under me. I half-woke and had a nasty shock -- not just that I couldn't feel my own arm, but it felt as if someone else's arm was in the bag with me! 
As far as the hand numbness, since you're in a line of work that'll probably require heavy keyboard use over the years, hopefully you're getting good advice about ergonomics, hand position, etc.
When I was at SAP, I had the pinky and ring fingers of my left hand go numb for a few months. It was diagnosed as "ulnar tunnel syndrome" (counterpart of the more common "carpal tunnel syndrome"). Luckily, my responsible German employer bent over backwards to accommodate me -- a thorough evaluation by an ergonomics expert, advice on changing my posture, a special wrist-rest, rebuilding my desk chair, etc. Eventually, the problem went away. But it sure made me appreciate having all 10 working fingers again!
Another arm! My gosh what a wake-up call! ;___;
Maybe Eich's arm dilemma was some sort of after-effect from his car accident :/
If it happens again you should go get it checked out, just in case.
My composer friend is starting to lose feeling in her fingers and hands, but the doctor said it must be genetic because she hasn't been in a serious physical accident recently. So maybe get it checked out if it happens again, just to be on the safe side Eich. :S
But don't worry yourself over it!
My book recommendation isn't really in our age range, (pffffft they're for all ages! You're never too old!) but I don't care, these are the best kick-back-and-relax books I've ever read:
1. The Bartimaeus Trilogy/Series
2. Lockwood and Co Series, both by Jonathan Stroud.
The Bartimaeus series has the best example of sassy sarcasm I've ever read, and the story is fun and the world building is really interesting. And the characters are fantastic. Really fantastic.
The Lockwood series is fairly new, about young ghost-hunters in London. I read it in one sitting because I couldn't put it down- it was really fun, pretty spooky and mysterious and really enjoyable ^u^ Plus, I liked finding all the shared points between the two series because there's a little fan-conspiracy-theory that th----- *ahem*
These books are like, my über passion. I'd be really hard-pressed if I had to choose between them and SSSS. O____O buuuut that's just me....
