Learning new skill or talk with foreigner, that's will bring you some fun

Learn a language

Watch a TV series film

Just go out and run

Boredom isn't a physical issue but a mental one. It happens when there either aren't enough activities to keep oneself engaged or the activities that are there aren't the ones that one inherently likes.

The solution lies in doing whatever it is that attracts and interests you and doesn't need other people. Even if there are other (uninteresting) demands on one's time, it's necessary to take a break to do what one likes so as to relax and refocus the mind.