The art of noticing
Just spent 4 days in New York City and went to exactly zero shows, concerts, parties, or museums. What we did do was walk around and sit in parks a lot. It was uncomfortable in the beginning. I felt myself getting bored and restless.
But after a while, I got better at getting entertainment from noticing new things. For example, in big cities every building has its own water tower on the roof. This is because the water needs to be stored above the level of the building to provide pressure for the faucets, and traditional water towers are shorter than skyscrapers. This is the kind of thing you only get to see when you give yourself time to notice things. Doing nothing is an investment in yourself.