That's been my policy, too. But it's often been said, "we make time for the things that are important to us". I am only important to the people who call me their Best Friend when they want something from me; when I need something from them, they don't know who I am.
Viz., someone who swore that we'd be best friends forever, because I did so many nice things for her, listened to her endlessly when she needed advice, bought her lunch when she was broke, etc. When things changed and I was the one who asked *her* to bring some take-out over after work, I didn't hear a peep from her for 5 years. Not one phone call, and only a birthday or Christmas card with a one-line note "we'll be friends forever". She was always "too busy" to call me, but found plenty of time to chat with other friends who weren't going to ask her to go a few blocks out of her way to pick up a $4 container of soup. Until she was getting married and wanted a present. I did go to the wedding and gave her something inexpensive (not the 200-hour stitchery she'd hinted for years she wanted from me), and in the 3 years since, have received one thank you note for the shower gift, one Christmas photocard, and a one-line e-mail thanking me for letting her know about a serious accident involving a mutual friend. I don't expect to hear from her again until it's baby shower time, when I will be expected to produce the time-consuming layette that she saw me knitting for someone else.
When I commented on this to a mutual friend (one who has two kids, multiple pets, a huge house to clean and a time-consuming home business, and therefore knows I won't ask her for help because her plate is already overfull), she confirmed my suspicion, that X hadn't called me after hearing I was getting divorced, because X knew how much of my time and sympathy she had demanded when she broke up, and was afraid that I'd make the same amount of demands on her. Z told her that her fears were unfounded, I wasn't depressed over the divorce, I was thrilled and doing interesting things with my life, and X wouldn't listen to facts. She knew this is the way she was, and was positive that everyone would be the same way.
The same applies to my being ill. X knows that if she were diagnosed with something incurable, she'd be a whiny demanding little brat wanting someone to wait on her hand and foot, and can't conceive of it that I might just want someone to come over and watch a movie to take my mind OFF my problems. Z has reassured her repeatedly that when we go to lunch once a year to celebrate our birthdays, I talk about other things besides my health, but she refuses to believe that I don't act the way that she would. I can't possibly have anything to say about current events, books I've read, new movies that look interesting, because if she were this sick, she'd spend her whole life crying and want nothing doing with the outside world that's going on and leaving her behind. (Yes, I'm sure she would. If she didn't just shoot herself upon getting the diagnosis. But I'm not her.)