Plans change! Get used to it.
As organized beings, we love order. We plan trips, dinner dates, and quiet nights in, to read a good book. But unexpected events often get in the way. Perhaps you are called in to work to cover for someone who is unwell, so you postpone your trip. Your friend may have a personal issue, which means you need to cancel your dinner date. Then, as you settle in to your quiet night at home, your family pays a surprise visit. Your plans change again.
Our plans are based on the assumption that the world is predictable. And, indeed it is. Events in nature unfold with a precise regularity. The future can be said to resemble the past. This fact allows us to predict the seasons, the orbits of the planets, and even the positions of the most distant stars. However, the human realm is rather less predictable than the rest of nature. Given the complex interplay between our beliefs, desires, and interpersonal relationships, we should not be surprised that our plans are always subject to change.
So, how should we respond to unexpected changes to our plans? Should we get angry? Should we curse other people? Should we stop making plans altogether? Not at all. We should calmly accept that some events are out of control. Embrace the change. Make new plans, and accept that they too are likely to change.