When Robin Williams died I wrote letters to my three favorite teachers: My junior year high school English teacher, my freshman year high school history teacher, and my 6th grade teacher, who I worship the ground he walks on.
I told them all that I wanted to tell them now, while they were alive and kicking, how much I appreciated them and how much they meant to me, and not at their funerals. And they all wrote me back.
I never got to tell my junior high drama teacher. Tell them all now while you still can.