I used to be a humorous person, but I gradually became a little stiff. How can I find my humorous self?

I suggest you go to see runaway comics, Doraemon Rice Edition, and some good-looking new Japanese comics, and then do some exercise properly, study hard, keep an optimistic attitude and feel the warmth around you. You will feel full, happy and not dull!

(by the way, I forgot to mention some novels ~)