From the mouths of babes

Not about usability per se, but it cuts to the quick of what's required when providing or designing something that's to be used by others . . .

From an op-ed piece in the Boston Globe, written by a middle school student seeking better alternatives for keeping kids off the streets:

You should always ask middle and high school kids what they think they
need, instead of only listening to grown ups tell you what they think we
need.