not mad about it = like
NO
to be quite good at something = can do it
YES
to be keen on = like
YES
My grandfather isn't a big fan ____ playing computer games.
OF
Peter is very keen ____ science!
ON
She isn't really ____ cooking...
INTO
Sarah is quiet good _____ dancing.
AT
We are interested ____ technology.
IN
I'm not mad _____ fishing.
ABOUT