Alice and Bob haven't seen each other for a little while, since Bob is out of town for a few weeks and they last saw each other one or two weeks before Bob left. (Maybe three. No one remembers and it's pretty irrelevant, so I'd appreciate it if you'd stop bringing it up.)
Alice says, "Things got kind of busy right before you left."
Bob says, "I wasn't invested in seeing you before I left."
To "be too busy to do X"..."busy" is just a question of priorities. Whether it was Bob's level of interest in seeing Alice, or the importance of the other stuff he had to do, seeing Alice didn't have a priority. It's not necessarily that Bob doesn't want to see Alice eventually; just that he has other stuff to get done. And emotional investment contributes, obviously. We'd never be "too busy" to help a friend in danger, right? "Can you hang on to the edge of that cliff just another hour, I'm too busy eating breakfast." No. Our priorities suddenly shift, we drop our knitting and resign ourselves to missing the dramatic conclusion of our favorite TV show, and we help our friend.
Clear sky, so many stars
Somewhere out on the Pacific
There is a big ribbon of moon.
Oh. Life is fun! Sorry about that. I forgot!