[iamnotwhoiam]

I like how Mike Tyson put it: "Everyone has a plan until they get punched in the mouth".

[carrolldunham]

neither of these are alternate formulations of the op

[iovrthoughtthis]

its not so clear cut. they both tackle the "plans are useless" but the "planning is indispensable" is implicit as anything you do in response to a challenging situation is a plan