system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do I feel happier when anticipating something than actually experiencing it?

I've been noticing lately that I always feel the need to have something to look forward to, but I usually don't enjoy it like I think I will. I find it hard to be "present" and tend to think of the next thing to look forward to.

Is this this a common phenomenon that can be easily explained?
gpt
When you anticipate something you're imagining it under your rules and your mind is free to create any scenario you want. When you experience it it's usually a let down because it didn't live up to what you imagined it would be.