I used to make plans and cancel them a lot for mood reasons. I usually was in a good mood and had energy when making plans, then after a few days, low energy and not able to do much. It took me quite a long while to be more cautious planning things. Learning I might not be up to it then.

I know for sure this could annoy people (even if my friend was understanding), but was it selfish? NO WAY! It was just me not understanding my mood swings yet. It was nothing I did on purpose. It wasn't like I changed plans to do something much funner, I changed them to stay home and feel like crap.