I've carried a small compact chain tool for 35+ years, but never used it except at home in my garage.
About 40 years ago my car broke down in the middle of nowhere at about 1 AM - a problem I could have fixed with just a Phillips screwdriver. Ever since I carry a basic tool kit in every car, and enough tools in my seat bag to insure that I won't have to walk home (And a phone and a $20 bill if all else fails.) The funny part is that I have never had a car or bike breakdown since - but the tools are still there.