I don't know, I think it's something to do with smacking the chop hard, then getting wind underneath it when you are airborne.
Hard to control, saps your energy quickly, then when you go down a board size you think "Wow, why was I on that big barge in the first place?"
A good rule of thumb is your weight + 20 litres is about right for normal conditions. Go either side of this to fill out your board quiver.
I weigh 85 kilos, and have an 80 litre wave board, a 94 litre slalom board, and a 125 litre light wind wave/estuary board. This spread works well for me