You'll pat your thighs and look wistfully off into the distance, or you'll say something like, "Hmm, makes you think --" when it really didn't, but what you're really --  — what you're really trying to do is change the topic.
ひざをたたいて 考え込むように遠い目をしたり 何でもないのに 「そう言えば・・・」と 言ったりします  でも実際は話題を 変えようとしているのです