Just as Dole said.
Life gets busy and hectic for many people and even though this goes on, it doesn't mean that they don't think about you and wonder what your doing and how your getting along. Many of them might be in your shoes, Farty where they just *don't* call as they have no idea how to just pick up where everybody left off.
I love it when my friends and I can just pick up where we left off. Our lives are extremely hectic but it doesn't mean we don't think of each other and want to regroup with each other once we have a lull in our schedules.
And if they are *really* your friends Farty, they won't think your stalking them.
Maybe you need to process where your thinking that they would even consider such a notion. If they were to do it with you, would YOU think of it as "stalking?"