Call when you say you will

What is your opinion on this topic? A guy calls you then says that he will call you back. You wait, and he doesn't call you. Do you get a little upset, a little angry, or just think that its not worth it and move on and forget about the guy? I, myself, usually mention it the first time and see what the excuse is. Then when it happens again I will just let it be, which is where I am at this point with a certain guy. He got home from work called, said that he would call after eating and showering, but he never did. I think that I am going to let him make the next step because right now its two strikes for him. I may not like a guy always wanting to be around but I also dont want a guy that is going to forget to call when he says he will, especially right now when nothing is at stake.