Some of my favourites, all related to learning:
#84-1. It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so.
#84-2. You can learn new things at any time in your life if you're willing to be a beginner. If you actually learn to like being a beginner, the whole world opens up to you.
#84-3. The opposite of a fact is falsehood, but the opposite of one profound truth may very well be another profound truth.
If I am willing to think of myself as a beginner, I do not hesitate to acknowledge that there are things I don't know. Which, in itself, helps learn what is needed. The more mastery or knowledge I gain in a subject, the more I become aware of exceptions and the existence of things I might not be knowing, thus making me a little less arrogant, less rigid, less cocky. And more willing to accommodate other possibilities, more open before jumping to conclusions and judgement.
Profound truths ("deep fundas" as young Indians say) and paradoxes are often found near each other.