That's the nature of a proverb. It's a concise unit of packaged wisdom. It's useful to have in your mental arsenal, like a function. Often it's useful because it contradicts the default wisdom.

Applied to the wrong thing in the wrong way, or on the wrong day (there are no rules)... it's wrong. This (ironically) makes proverbs and religion a bad mix.

Don't argue with the devil. Measure twice, cut once. Grab the bull by the balls. Great company at a fair price, not fair company at a great price. Show must go on. Show, don't tell. It's how you use it that matters. Who cares what colour the cat is. Quality over quantity. There but for the grace of...

If you like your statements airtight, you don't like proverbs. Airtight statements require too many words. We can find exceptions to all these rules.

EDIT/PS: reading over what I wrote, proverbs are interesting. proverb meta analysis required.