The difference between pleasure and engagement is, one is passive, the other one is active. Engagement gives more happiness than pleasure says martin selectman. We want more of it afterwards to get the same level of satisfaction - that's how economics works. A late capitalist society more and more of this, you get more.
Swami Sarvapriyananda teaches the Katha Upanishad, which is one of the most popular Upanishads. The scripture concerns the story of a young man who goes to the house of death to find out what happens after death. The reply describes the nature of reality and the meaning of life.