Should you think more than twice about something you need to think about on more than one occasion? That depends on the type of person you are, and/or what that something is.
How often do you intentionally get yourself into things about which you don’t know much? And how have they generally turned out? Do you seriously wish you would get yourself into things about which you didn’t know much more or less often? There isn’t a right or wrong answer to any of those questions. You are who you are, although if you seriously wished you would get yourself into more things about which you didn’t know much, you might want to plan on how you’ll make that happen as it won’t likely happen on its own.
What’s the difference between wisdom, and conventional wisdom? Shouldn’t wisdom be sufficiently universal and timeless you shouldn’t have to qualify it with anything? And why conventional, of all qualifiers, meaning generally accepted as if common sense rather than wise knowledge known to a few? In that sense, conventional wisdom is an oxymoron, which is hardly wise, symbolically or literally.