These people who go quiet for weeks then start talking again, wonder what happens to the other people they prefer during those times?

This guy has gone cold 3 times since March and for a few weeks in between sometimes he'd seem interested. If I remember correctly once I've moved onto someone else my feelings won't return for the other person. There's 1 person who it managed to start up with again when I was really depressed.. 4 months had passed then though.