Let's talk about efficiency. The efficient use of our resources to extract the maximum possible pleasure from them.

If I have a food but I am not hungry, I save it for when I am hungry. Then I will enjoy it much more.

If I have a big chocolate and start eating it, every bite is an experience of pleasure. But by paying attention to each bite, I can perceive that after the first few bites, the next ones are generating less pleasure. I'm not enjoying it as much anymore. I'm finishing it because I have it. If I put it away and eat it another time when I feel like it, I will get much more pleasure out of it.

Following this logic...

I've eaten half of the chocolate and a friend comes along who has a sweet tooth. I could finish eating the chocolate, but it is natural to feel that it would be a waste for me to eat it when he is going to enjoy it much more. In him, this chocolate can generate much more pleasure, it yields more.

We all have that feeling with some people, or in certain contexts. Some with a circle of a few very close people, others with a larger circle of people.

The fact of not being able to conceive in any way that their pleasure makes a sum of pleasure of which I am a part and whose growth is my growth is egotism, ignorance. In Sanskrit asmitá and avidyá.

To expand the consciousness is to widen that circle of persons and circumstances. It is to run that frontier with which we delimit if the pleasure is our own or someone else's.

The goal of Yôga is to eliminate that boundary completely.