I used to be insecure and then I ran out of patience

Something funny happened yesterday. If I was younger I would have been mighty upset and tried to resolve matters and misunderstandings. Now, I don't care enough to bother. The day before or the night before last night I had to stay up all night to work and the delivery was scheduled yesterday. Everything went as planned and the final checking was done late evening and as I waited for the final phonecall I must have dozed off. I was also unwell and was having mild bronchal asthma attacks that are normal for this time of the year. I woke up to hear the phone ringing and I didn't bother to check the number since I was so sleepy and I assumed it was for work and in my best contrived efficient yet still-groggy voice said, "Yes, X tell me." The voice at the other end belonged to the ex and in a strangled voice he yelled, "I am not X." I had not told the ex about the job (why should I have?) and putting two and two together, he assumed that I was awaiting someone else's call. Normally I would have blundered through and tried to explain, but now, I just do not care. I patiently and tiredly heard his rantings and then he said goodbye in a very theatrical manner and hung up. When people make assumptions I let them. It is often amusing to see how wild imaginations can get, especially if the relationship has been even vaguely romantic. I suppose I should care more, but I get pretty disgusted by the insecure.