Today, My SuperPower Was Replacing Keyboards
It all started when one of my users spilled coffee on the arrow keys (it's always coffee)
The repair went very well - I had enough time to check another problematic keyboard! Turns out the second keyboard was not connected properly after a visit to an Apple Repair Center (!)
If you're over 50 (like me) and you wear contacts, pop them out so you can see what you're doing.