Is there any legitimate scientific explanation as to the following habits of mine and why they're so satisfying?

1. Picking my nose and rolling the snot between my thumb and index finger until it's reduced to nothingness
2. Using my finger to extract ear wax, then rolling it in a similar manner as above
3. Rubbing dead skin cells off my neck and then rolling them as above
4. Sticking my fingers around the base of my dick and also in my inner thighs, and then smelling them
5. Anytime I fart and am alone, I have to pull my ass towards my face extend my neck so my face is right up to my ass and I can enjoy the fragrance