The act of embracing something, or a situation, by using it to empower yourself. To “lean into” something is to own it, to cast off disparagement. You move forward and
deal with it with unhindered
confidence, casting off concerns and cares.
Instead of letting a shortcoming hold you back, you find acceptance in the situation, perhaps even going as far as to pride yourself on it. “Leaning into it” may even imply doing more of the “thing” in question, or highlighting it, as a means to overpower it and have it no longer be deemed a weakness or
unfortunate hangup.
The phrase may have risen itself from the physical act of bracing yourself against an impacting force, in the same way a person may tighten their stand against an incoming tidal wave.