let's be honest we all like the smell of our own fart.
People hate to admit it but the truth, we like the smell of our own fart!
Personally I'm very proud when my fart smell very bad... I feel like I did a good job!
Also people scratch their ass and smell it... why? It's a leftover instinct from our primal past. Apes do it all the time. It was a way to know if we were healthy...
Also believe it or not eating your boogers is good for you
http://articles.mercola.com/sites/articles/archive/2013/05/13/nose-picking.aspx
If you want to have a good laugh read
http://isitnormal.com/story/i-like-the-smell-of-my-own-farts-26174/
http://isitnormal.com/story/i-like-to-scratch-my-ass-crack-and-smell-my-fingers-58973/