the view from your deathbed

I sat in a coffee shop yesterday. A man walked in and caught my attention. He seemed familiar. Perhaps it was the way he walked, the way he held himself, or the way he greeted the staff, but I knew him. I just didn't know from where.

He sat across the room from me and ordered a coffee. Black, no sugar. Mine was almost finished and I gestured to the waitress to bring me the same. We made eye contact, he smiled. He went back to scribbling on the piece of paper he had in front of him.

The waitress returned. As she handed the man his coffee, he slipped her the paper and asked her to hand it to me. Her confusion matched mine, but she obliged. Next to my coffee lay a note that read:  

The man's table was now empty, except for another note he left behind, that read:
"I came to you because I know you needed to hear this. I wouldn't have wasted my time otherwise. One of the few luxuries we have as time travellers is that we may visit our past selves."