When we think of the question "Why didn't he call" of course we're talking about the dating world, but the truth is that sometimes we connect with a new friend and then wonder why they don't follow up after. I just talked with a woman who met someone during a group activity that she really connected with. Both gals exchanged phone numbers and promised to get together again soon.
The woman went home, and waited. No phone call. It made her feel exactly as if she were dating and had been stood up by a guy promising to call. Except that this time, it was a woman who she hoped she's be friends with.
Dating and friendship are sometimes related, aren't they? You have to put yourself out there, make conversation, and then trust that the rapport you've built is enough to encourage the other person to get to know you further. Waiting by the phone for a new friend to call can feel just like waiting for a date to call.
But just like when you're dating, the best thing to do is not wait by the phone! Get out and be busy. Get to know more people and try to make new friends. Then, if a new friend calls - GREAT! If not, no biggie. You gave it a shot.