evrytime I "think" I'm prepared something big breaks
But if you've done everything possible to prevent such incidents, at least when something happens (which it will), you don't have regret or remorse, saying, "I wish I've done....." Which is the killer to me.
Things will break (or people will hit you

) but thats pretty much out of your control to a point. If you know something is in question, and let it slide, and it fails causing mayhem, more money, or worse, injury, then that really hurts knowing you could have prevented it.
I learned a good lesson 10 years ago when I use to tow cars. Everything will break down. Don't care if its a brand new Mercedes with under 100 miles (which I've towed), brand new Harley's, (which I've towed), or Old 'jalopies' with 500k+ miles on them. Things will break down. Just have to roll with it when they do.
But its always worse when something you know is in question, and it breaks causing loss of money or worse.
My theory is, if you do 10 things to your rig, and 1/10 prevents a mishap, then it was worth it.
Unfortunately with the poor quality of replacement parts lately, i've also been burned by doing preventative maintenance on items that weren't failed yet.