I was a total bike fiddler loser pre course.
They taught brake adjusting, rear gear alignment, changing brake/gear cables, front and back wheel removal, alignment and replacement, changing tyres, puncture repairs, pre ride checks, post ride cleaning, what to put in your saddle bag/rucksack when you go out, a brief guide to making a spare bike fit you (if you borrowed one).
...and possibly more but wine has broken my brain!
I can't say I'm competent.... but I'd now have a go especially if disaster struck out on a ride.
It was really useful ☺