feeling a bit guilty

One of my coworkers relayed the message to me, yesterday, that an ex-coworker would like me to phone him, and that said ex-coworker is 'not doing well at all.'  So I told him I would.  And I was really going to do that this morning, but...  I didn't.  I don't know what else to say about that.  Now it's going to have to wait until Monday, and I hope that's not too long.  Though I don't know what I can do for him besides listen to him complain.  I mean, not only is there nothing I can physically do to help him, there's also pretty much no chance he'll listen to any opinions or advice I may have on his problems, as he's always been completely sunk into his view of the world.