Picture the scene.
A fifty year old mum, newly converted to running, and her 14 year old son are in the car. As usual mum is taxi-ing her son around as it the way in the school holidays.
Mum: Kate (mum's lovely but lovely bonkers friend) has suggested I do a 10k race. I don't know if I fancy it really, just happier pootling along on my own.
Son: (feigning interest) Hmmm.
Mum: I suppose I could, now I know I can run 10k.
(There is a pause, as said son assimilates this strange concept)
Son: Isn't that the same as Mo Farah does?
Mum:(feeling pleased with herself and just a bit smug) Well yes it is as it goes.
(A further pause for more thought)
Son: (with a huge grin on his face) Doesn't he do it in about 20 minutes?
Mum: Get out of the car!!!