haha, i started after L's bath on a cold winter day when i found it chilly in my apt. I also knew some parents used the hair dryer as white noise and i thought "i bet he would like the heat that comes out of this too!" and he did! It was pretty funny the first time I ran the hair dryer over him, he looked so confused but didn't move and just let me do it! Now I do it after almost every diaper change (to keep his bum dry in an effort to prevent diaper rash) and he just relaxes when i do it and i can tell he likes it! Babies are so funny.