Not scared per se, but anything power has to be respected. I make sure I understand to only the proper use of the tools but their danger points. The worst I've been injured so far (Not counterfoil minor scrapes cuts and burns) is:
Smashed thumb from an older Hi-Lift/ranch jack lowering a tilt cab. As the weight decreased the jack handle started to go faster, then whip back and forth, and slipped from my right hand and smacked my left thumb (I was holding the top if the jack). This one has a 36" wood jacking handle and I was standing almost four foot off the ground in the flat bed, and there were tools and junk all over behind me on the ground. My body wanted to flail backwards and stopping that reaction was one of the biggest feats of self control Ive ever done. (I did straighten up and teetered on my toes before stopping) Forced my body to not move while it was saying "JUMP! YOUR HURT"... (I had to go to the ER later that night as my thumb swelled up and they had to punch a hole in my thumb nail to relive the pressure)
I was (foolishly ) drilling a hole in some plumber tape with a hand drill and holding the tape with my left hand, the drill caught, wrapped the tape, and my thumb and for finger cutting both pretty good. Just a split second before it caught, I thought to my self "this is stupid, stop and get some pliers"...
Then there was the bicycle incident, but that wasn't a power tool.
Probably the tool I'm the most careful with is a router when using it by hand. Exposed bit and 8-10K rpm...
That and the rest of my power tools; Radial arms, DP, table and band saws, lathe, mill, etc... Not to mention innumerable hand power tools, I stop and look before hitting the switch or starting a cut...