hmmmm.... 
My Mom used to listen to the radio a lot, and in those days Springbok Radio was a lot like RSG now. They had many talks and stuff and one day they had one about stress and stuff. The mentioned that in a study in America, it was concluded that some of the top things to relax the mind was:
A) The sound of running water (i.e. the ocean, a river or a stream);
B) Watching fish in an aquarium; and
C) POPPING BUBBLE PLASTIC!!! This is considered as "constructive vandalism" - I mean, HAVE YOU EVER!!!