Your brain is designed to run on pleasure.

Even single cell organisms make peptides and endomorphines and live on a seeking of pleasure for survival.

A peptide is an emotion chemical made of amino acide combinations.
In our brain they are manufactured in our hypothalamus.
All of our cells have receptor sites for various peptides. Sometimes a chemical will have the correct electrostatic charge and size to fit in the keyhole of a receptor that opens up to the outside world of a cell. Some of these chemicals that we do not produce are called andogenous ligants. They might be LSD, MDA, Mushroom alkaloids etc. that fit into a variety of our cells receptors even though our recptors are for peptides that our hypothalamus produces based on our own thoughts.

So your thoughts will determine how much pleasure you let yourself have.