Quote Originally Posted by dbat74 View Post
Common sense comes into play here as well. But if common sense was so common more people would have than not.
"Oh, I've done that thousands and thousands of times, and nothing ever happened." If you do something not so smart, and it doesn't go bad the first time, how do you know it was a bad idea? Eventually you'll figure it isn't a problem because nothing bad ever happens. Until it does. I collect aphorisms. Here are a couple of them on experience:

Good judgement comes from experience. Experience comes from bad judgement.

The only reason I know anything is because I've done it wrong enough times to START to know better

The problem with gaining experience is that sometimes the result of gaining that experience will kill you. Was a young lady died some years ago working alone in a college machine shop. Ivy League, IIRC. Got her long hair caught in the chuck on the lathe she was using, and died. I know she was told that was dangerous.

My school will throw you out of the class if you keep making safety mistakes like that, and the instructors WILL call you on them. We aren't allowed to use the machinery unless an instructor is there.

And as others have commened, common sense is not so common as you'd like to believe.