The book explains it much better, and I can't quite remember it, but it's all to do with memories of things staying (or shining) in the hotel. Time has sort of been mixed up, so things from the past meet with the present, and remember "you have always been the caretaker"
I have lots of faves but if I had to pick one to watch again and again it would be the Pretty In Pink. God I wanted to be Molly Ringwald when she got with Andrew McCarthy.