Going off to college means saying goodbye to your parents more than just on move-in day your freshman year. It means saying goodbye every time after they visit you or you go home for the weekend or a holiday break.
Last year, I was a quick 2 hour and 30 minute drive away from home, which essentially enabled me to go home for the weekend whenever I felt like it (which, by the end of second semester, was very frequently). Because distance wasn't a huge issue and I was able to come and go as I pleased, I never understood the value of a goodbye. Yes, it always involved a big hug before I drove off, but it was more of a "see you in a few weeks" rather than "see you in a few months."
But now, I'm a good 8 hour drive away from home, and that's being generous. And while I personally enjoy driving long distances by myself, it's definitely not possible to wake up one morning and decide to drive home that day, spur of the moment.
This school year I'll go home twice--once for Thanksgiving break, and once for Christmas break. And after that? I'm not sure when I'll be able to go back. Between study abroad, interning, and summer classes, I may not have any time to go home over the summer. And with the potential for that being the next two summers, the only two summers I have left before graduating, I may not spend another summer at home again.
Which means that the time I spend with my family either when they come to visit or I go home is just that much more valuable, and every hug goodbye is that much harder.