You see that young lady's face up there? That's how I look the moment I realize certain people aren't worth my time. There's something about the L.A. air that turns the most humble, considerate human being into a "friend" hopping, 'hey when's it start,' grass is-always-greener-on-the-other-side somebody who won't hesitate to drop plans with you to hang out with someone else who has more to offer them.
And I'm here to tell you, it's about them, not you, so please don't take it personal. In fact, dealing with flaky people can build up your resolve to be your own best friend. When I see something I actually want to brave traffic for, I go by myself. I don't spend time asking who wants to go with me. It's a waste of time, and tends to reveal even more flaky people.
If you find yourself on the end of an encounter with a friend, real, imagined, or potential who frequently doesn't reach back, when you reach out - don't take it personal. Real recognize real, and they just aren't it.