I agree with 'cheap insurance' comments!
I've been using a chainsaw for maybe 30 years and the first 20+ of them, I never put a thought into safety. Wasn't until finding this site that I got some chaps.
Just a couple years ago, we had the farm logged. There were several cedar logs they cut/left behind for us. Wife wanted me to take one of these logs and cut a SINGLE "step" from it. Meaning, cut a section of the trunk so I'd have a disk maybe 6" thick, full diameter of the trunk.
Why put all my stuff on?
I jumped on my backhoe so I could raise the tree off the ground, everything was as safe as could be. I only needed to make two cuts. One cut to knock off the root side of this which was ragged and another cut 6" further up to give me the disk she wanted.
I was making the second cut when my chain jumped the bar. I did NOT have my chaps on

The little chain catcher thing on the saw (Stihl 044) is what caught the blade from rotating any more however, the chain did slap the dickens out of my kneecap and left a rough mark on my jeans where the teeth hit the jeans and picked at the fabric a bit.
Had I not been wearing my jeans would I have been cut? dunno. Had that chain guard not been at the base of the blade I have no doubt the chain would have had more of my leg for lunch.
So here I was simply making two stupid cuts under VERY controlled conditions (backhoe holding log for me) and still came close to having an accident.
Now, I simply look at my saw as a living enemy who WANTS to bite me any time, any way, any how that it can and it's up to me to be 100% vigilant on protecting myself even if I'm "only" going to make a single cut or two.