On the aforementioned flight home, I sat next to two girls who had just graduated from UC Davis the day before and were now headed to Spain for two months. We had some pretty good conversations, and they seemed really cool.
To practice my social bravery, I forced myself to screw up my courage to ask them if I could buy them a drink to celebrate their graduation since we all had a couple hours' layover at O'Hare. I finally did so, and they politely declined, but at least it served to reinforce in my head the reality that the world doesn't end when things like that happen.
So I had a beer by myself anyway, and you know, it was just fine.