Out of sight, out of mind?

Does anyone else struggle with staying in touch with people they don't "have" to see on a daily basis because of work/hobbies/...? I tend to make friends quite easily and get deeply connected with some of them, but as soon as I or they relocate or switch routines, I can't seem to stay in touch with them, even though I love them. Sometimes, one of them randomly pops up in my mind, so I send a message, but then I forget to answer when they respond.