One great lesson is dying people are still living. You know, it's like, to realize it and see it as part of life, and to separate dying from being dead. Dying is these final moments of life, and therefore are very potent, essential, really concentrated part of life, but it's part of life.
That's (what) the first lesson is, alright, dying is part of the deal, and I'm still living when I'm dying.
You start realizing that what makes anything precious except that it ends. So dying is what creates preciousness, what gives us the impulse to make meaning, because death proves life. You know you're alive because you're gonna die someday.
Another big thrust of this is, what you learn is, time is short. So the decisions you make are of consequence. Delaying things that you love or want or seek, not calling grandma, whatever it is. You have no promise of tomorrow. So live your life today.