Shared complaining-about that loud jerk behind you in the bar or the weird cabbie or that song you both hate-can help form bonds. But if you're flying off with complaints about your job, neighbors, and friends, well, you're just a downer. It's never interesting or pleasant to listen to a near-stranger airing their grievances. Keep it positive, and if you can't do that, at least keep it amusing. Angry-funny will at least produce laughs instead of the nervous chuckles elicited by angry-bitter.