At the very instant that you think, "I am happy," a chemical messenger translates your emotion, which has no solid existence whatever in the material world, into a bit of matter so perfectly attuned to your desire that literally every cell in your body learns of your happiness and joins in.
Deepak ChopraThere is more and more data that the biological molecules of aging are more under the influence of psychological factors than the chronological age that we usually associate with. Of course there are other things that influence our aging process, including how we perceive time. If you're constantly running out of time, then your biological clock speeds up, and you do run out of time with a heart attack or something like that. The quality of our self-esteem determines how we age. Our perception of our bodies as fields of energy or fields of matter influence how our body ages.
Deepak Chopra