Dopamine changes how we remember past events and their timing.

“if something that you experience is fun or varied, meaning it has a lot of different components in it and is in other words is associated with an increase in dopamine in your brain. You will experiencing experience that as going by very fast. Imagine an amazing day for a kid in amusement park. They can do a ton of things. It's all new. They're very excited and they'll feel like it goes by very fast, but later they will remember that experience as being very long, that it was a long day full of many, many events.”