From Psychology Today:
Peak experiences often involve an epiphany, an aha! moment that occurs suddenly, typically during a period of emotional turmoil. In an instant, we have an insight that is entirely new and deeply meaningful. We might realize that we can’t stand one more day working as a corporate lawyer. Or that heavy drinking is ruining our life. An epiphany can reorder our priorities, revealing how we’ve veered away from our authentic self and inspiring us to move towards behavior that better matches it. The transformation is usually enduring.
There’s not much in the way of data there, but they quote psychologists Jeffrey Kottler and Roland Griffiths, a Johns Hopkins researcher whose meditation practice led him to study dramatic change and psilocybin, according to his TED talk posted below.