Earlier quoted context omitted.
It didn't take me 30 years, only 15, but I did develop problems - RSI in my arms. Luckily, it recovered, but it took a lot of effort: http://henrikwarne.com/2012/02/18/how-i-beat-rsi/
As a 30yo dev, I started getting pains in my wrist, and numbness on one side of my hands (the pinky and finger-next-to-it). I switched to a ball-mouse at work, and no longer get this. I believe the large amount of time using a mouse had compressed and damaged my nerves somehow. I'd recommend the switch for anyone spending hours with a mouse.
Typically, if the issue is worse when your arm is bent, you know it's that. Just wanted to save you some trouble googling things if it happens to comes back.