Wait and see
“Forget much of what you learn” and “Be slow-witted” became two of Montaigne’s best answers to the question of how to live. They freed him to think wisely rather than glibly; they allowed him to avoid the fanatical notions and foolish deceptions that ensnared other people; and they let him follow his own thoughts wherever they led—which was all he really wanted to do." (Sarah Bakewell, How to Live)
Montaigne is in the first tier of my personal Pantheon, and this is one of the many reasons. I am naturally glib, modern times reward glibness far too generously, and so I thought my highest end in life was to share what I'd learned with someone, anyone — in fact, to learn as quickly and broadly as I could just so I'd have more to share. No. Learning is important, but only in order to put it to the test and then discard what doesn't work.
I eventually figured that out. I would learn something new but hold it lightly, waiting to see how it fared in practice. Usually it didn't fare well at all — something that true believers were quick to ignore, since they were invested in its truth, would benefit from it being in fact true. Most of the "truths" I encountered turned out to be wrong or at best useless, and once I recognized that I quickly unlearned them, noting only that I had found them wanting and shouldn't return to them. It helped keep my mind clear for the next thing to learn.
A few things passed the test, but even then I was slow to embrace them because I wanted to be sure. In that sense I am slow-witted. When something new comes along, my habitual response is "Wait and see". And those few things that stuck around have served me well.