I'm not big on goodbyes, because, for me, goodbye is usually more like, "Well, I guess it'll be a few months to a year before we see each other again."
I feel like I tend to see everyone again. Partially, this is because I've spent most of my time in two major metropolitan areas (the Bay Area and DC) that tend to draw people to them. But, basically, I've found that I almost always see people again. And it's often sooner than I think. If I was into saying goodbye, then I'd end up saying way more goodbyes than I needed to say.