Our expectation increases along with excitement, and as a result the event itself doesn't feel grand. We don't enjoy the festival as much as we'd thought we'd enjoy.
The festival ends, and you feel sad again that the festival had to end. Basically, you get excited before the event, don't enjoy the event and feel sad that the event has to end.
We're not enjoying the event itself, so there's only sadness during the end. Instead of making it work this way, we should try and focus on the event instead of the before and after. The before and after barely matters. In fact, it doesn't matter at all.
If we give too much of our focus to before and after, we'll miss the event. Focusing on event should be the main goal. And it will guarantee that we'll enjoy the event.
The reason we feel extremely excited before the festival is because we have memory of our past experience during the festival. You expect something similar. But the problem is that expectation reduces the joy of life.
If you expect something before hand, the event itself won't be as fun as it could have been. The reason past experience were joyful was because you weren't expecting it. You didn't know what to expect. So, it was fun and exciting.
However, when you grow up, it doesn't feel exciting as much because you use the past memory to set the expectation. That's why you feel extremely excited before the event and feel sad after the event because it didn't meet your expectation.
For example, we have Dashain and Tihar festival here in Nepal. It just ended and I'm feeling sad somewhere. Feeling sad that I didn't get to enjoy as much as in the past. That feeling stays only if I compare the present with the past.
For me to enjoy this event, I shouldn't set any expectation and enjoy it as it comes. I should do this my own way instead of persisting to have it like the past moments.
I was excited when this festival started and I'm sad that this festival had to end. But didn't enjoy the festival itself.