Steve:
and I could be misquoting, better to keep silent and be thought a fool than to open your mouth and prove it.

Unfortunately that appears to be one of those aphorisms which occurs in two conflicting forms, like 'look before you leap'/'he who hesitates is lost' or 'many hands make light work'/'too many cooks spoil the broth')
I recall it as: "Better to keep silent and be thought a fool than to speak up and remove all doubt".
The converse is: "Better to speak up and be thought a fool today than to remain in ignorance for life" (or some such)

Cheers