My son is close to CPL.. and of course he gets upset when i explain to him how to
fly on the edge.
I mean, really, I'm only an experienced parent who knows sweet f-all

BUT.. he is an excellent pilot. Must have the same attitude like the old man ??
One must consider that in a glider you do not have to worry about any engine and it's side effects, but at the same time you're more experienced at the finer points of flying with regard to non-powered flight(or pure flight), which is something that should be taught at PPL level on powered a/c.
Maybe PPLs should start with gliding

after all .. the Luftwaffe aces all started here !!
Edt: there have been some raised eyebrows here, when I've mentioned
cross-the-controls to get the best turn performance out of a FW .. i just laugh away.