"Mackerel are superb swimmers."
They're fish, ffs. If they weren't superb swimmers, they'd be complete failures at being fish.
Reminds me of early-year parenthood, where people were obsessed with trivia like what age the toots started walking.
"Ooh, he's walking already, at 10 months! Such a clever little toot!"
"<panic> Our little toot is not walking at 11 months! Wail!"
What a load of tosh.
How many parents sit around look at their 18-yr olds oaves and nattering:
"Ohh, look how well he walks! I bet he was walking at 10 months!"