Ken Bruen, "The Guards"

"Did you ever love someone?"
"There was a woman, when I was in the guards. She made me feel more than I was."
"That's a good feeling."
"But I screwed it up."
"Why?"
"It's what I do best."
"That's no answer."
"I could say it was the booze, but that's not true. There's a self-destruct button in me. I keep returning to it."
"You can change."
"I don't know if I want to."
On that sombre note, we went to sleep.
She was gone when I woke. A note on the pillow,

Dear Jack,
You're a lovely man. Don't self-destruct on me.
I couldn't bear it.

Xxxxxxxx
Ann.

I wasn't sure what I'd let myself in for.