To have some knowledge is to be prepared, and that is very good for any circumstance that may occur.
I don't know about mechanics but I know how to change a water, gas or electricity pipe. I have done it. Mechanics often rip people off because people don't know about these things.... masons too, but I am prepared and I know how to do the job, to give an example.
It's important to know a bit about everything and to be prepared.
Some understanding is better than none and could help towards keeping others on the straight and narrow like tradespeople and mechanics for instance.
Understanding is very good for everyone!