Now, either we're all just becoming really grumpy as we get older, or it may mean that as you understand laughter better, and you are getting better at doing that, you need more than just hearing people laugh to want to laugh.
歳をとるほど気難しくなるのか あるいは 笑いをより深く理解できるようになって 対処が上手になるのかもしれませんが 笑いたくなるには 人の笑い声を聞くだけでは足りません