Favourite pieces

As all of you, I have also my favorite pieces of music. Not all of them are from the classical repertoire, but I can listen the favorite piece 100 times or more with the same enthusiasm and without feeling bored. It put me in a very relaxed state of mind and recharges me with the positive feelings. 

The question is: why do we have this preference for some pieces more than for the others? It is a subjective perception, a matter of taste or it`s something more than this? It`s there a "specific technique" to compose this songs? Maybe a composer can illuminate us :-) I`m wondering because I saw on YouTube melodies for relaxation, meditation, for inducing sleep, etc... I was listening some of them but in fact I`m not sure if they really had the desired impact over me. 

Anyway, listening to my favourite pieces it always works and it helps me to change my mood and to relax in a way than no other activity can do it for me.