<human>: Can you provide a brief rundown of the text in within 3 sentences?

I used to go to school with this guy for years at a small school, k-12. We basically went to school together since we were 5, up until 8th grade. I just ran into him this weekend at a general store after he recognized me in the parking lot, and tried to talk to me about what I was doing, what I was up to, but I was sort of busy with friends because we had to leave. I feel bad because I made awkward conversation and was EXTREMELY hungover and tired. I basically had to end the conversation with something along the lines of saying I'll write to him on facebook.

I feel horrible and embarrassed because I was so tired and hungover, and could barely hold a decent conversation, and then cut it off quick. I'm also embarrassed because he's a successful attorney now, and I'm unemployed with no career trajectory. He was so extremely nice, gracious, and interested in what I was up to that I wasn't sure what to say, but I wanted to reach out and follow up with my promise that I'd write to him on Facebook. So here I am, wondering what I should say.  I don't really want to talk about my employment, but I do want to let him know it was really nice to see him.

What can I say that sounds very kind and mature? Are there any words that particularly make people feel good in general? I know this sounds stupid, but that's because I am stupid.

Thanks.
<bot>: ran into old elementary school classmate who is very kind and nice and successful, told him I would write to him but am not sure what to say, help?