Being nice to someone does not mean you have to be their doormat. Sometimes it feels good to surround yourself with people who have it shittier than you, so that you can say to yourself, "Well, at least it's not that bad for me." The trouble with this approach is that they suck all your energy, they can't help it and you have to give it, and at the end of the day you have nothing and wind up dragged down with them.
NOT A GOOD THING.
Being pleasant is fine, getting any closer is probably not healthy. And when this guy at the bar dies, and you need a shoulder to cry on? Who will be there for you?