Not just reading our textbooks and memorizing is learning; it is boring. Suppose you are reading one of the concepts States of Matter, and you are reading about the matter. Then you can think of five-ten things and write them down in which form they are and more factors such as size, shape, mass and colour. This will show the concept in the real world and make learning so much more fun.
My science teacher always tells us to visualize things and draw them. It makes it so much fun, in your science class you can draw several diagrams and learning is fun!
When I revise for my exam, I put all my notes of different subjects in envelopes and send them back to me through the bottom of my room's door. It's like receiving a letter with notes. While revising for my English exam, one of the topics is a formal letter. I wrote a formal letter to the principal, put it in an envelope and acted as if I was the principal!
So there are so many ways in which learning can be super fun!