Happiness is something we spend our entire lives trying to find. However, when we think we have found it we're mistaken. It can easily be mistaken for pleasure.
True happiness is associated with the good Life. It's about seeking knowledge and nobility (virtue).
The main difference between the two is that happiness is permanent or life long whereas contentment is temporary or short lived pleasure. According to John Mill's Utilitarianism theory, humans experience two types of pleasure: lower pleasures and higher pleasures. The lower pleasure, however, are the ones associated with contentment. They are based on the body and are the ones we're born with; not acquired. The higher pleasures are those of intellect and must be cultivated.
In attaining the higher pleasures, they may be challenges encountered. However it is still desirable because even if you fail to achieve the higher pleasure you build a tolerance to pain and have put so much work in that you are not so disappointed.
