Slac wimp detector
That's what our PE master thought he was in the 1960s. As a result my only real prejudice is against Welsh rugby players who become psychopathic PE teachers. Because I was a very slack wimp.
Fortunately the Head agreed with me and he was asked to find alternative employment, but not until after he had put me off school games for life.
If they'd opened up his skull I'm sure they would have found plenty of very dark matter indeed, (And I'd have offered to operate the trepan.)