I was always real careful while cutting, then one day stuck my hand into the blade reaching over to clear out some scrap after a cut.

Luckily I was wearing super thick work gloves in the cold of winter, but it still wrenched my thumb so hard as it threw my hand back it was swollen and blue for weeks. (And ripper the glove all the way through).

Lesson learned: Be super careful whenever that blade is spinning, not just while making the actual cut.