Out of sight, out of mind
Definition 1 of 1
Pro Tip 1/3Emotional Detachment
Used when emotional ties fade as people or things are no longer seen regularly. 
They parted ways and soon, it was out of sight, out of mind, as they both moved on.
Pro Tip 2/3Short Attention Span
People often lose focus on things not immediately before them, leading to neglect. 
Once the video game was put away, the kids were out of sight, out of mind, playing outside.
Pro Tip 3/3Not a Priority
Some people or tasks become less important when they are not in one's daily environment. 
With the old car stored in the garage, it was out of sight, out of mind.