"Oh pa, young Clark is surely asleep, now slip me the length!"
Goddamn, that's why superhero stories work best for the young and/or very naive.
Although any kid who perused the "X-Ray Specs" ad on the inside back cover of a National Periodicals comic back in the day probably figured out what was up pretty quickly.
I imagine that the whole notion of someone like Superman "learning to use his powers" has as much to do with learning how not to use some of them - like hearing and vision when they would be troublesome - as it does with mastering the proper techique for lifting a skyscraper off its foundation in one piece. I mean, Clark can't go through adolescence with a Super-boner from passing girls in the hallway at school, can he (actually, he probably would. Or "wood")?