It is an expression the speaker says to the listener to encourage the listener to be extravagant, to go all the way, and do whatever you are doing to its fullest - and not flake out.

Im not sure, but I guess it means like: you either do something great(big) or you just stay at home and dont do anything at all. Maybe it's close to the Chinese saying:一不做二不休？ 要么就不干，要干就干大的。 Just a guess. :)