I sat opposite Pete Shelley on the Northern Line once a few years back.
I was already smashed but engaged him in some high end intellectual conversation. Along the lines of:
'I knows you but I can't remember your name cos I've had a drink. Ever fallen in love, man I loves that. Must drive you mad, drunks on tubes haranguing you?'
He was very good about it, and we had a right good natter in the end, to the point we ended up both getting off at Camden for some late night sight seeing.