1. if you don’t see someone or something for a long time, you'll eventually stop thinking about someone or somethng

1. Ever since I moved, none of my old friends have gotten in touch with me. It’s out of sight, out of mind with them, evidently.

2. My electric bill somehow got moved to the bottom of the stack on my desk, and I forgot all about paying it. Out of sight, out of mind.

3. Problems in remote places can be out of sight, out of mind for many people.