Even if a group of people share the adoption of joy as their purpose, there will be tremendous variations between how they define joy. One dimension of this difference is how much they view joy to be a function of what they are able to do for others versus what they do for themselves.
It’s easy to see joy as a uniquely selfish pursuit. Surely, there are ways that joy can be pursued and obtained that place self before others. However, if your motivation is limited to your own progression, you will hit an absolute limit in your improvement, and therefore a limit in your joy.
The fact is that the path of self-improvement for the sake of self quickly hits diminishing returns, where the increased sacrifices necessary to continue improving can’t deliver sufficient benefit to self to make them worthwhile. Since joy comes from improvement, the diminishing returns of improvement for self create an unsurpassable asymptote in your path to greater joy.
The greatest joy is only available in improvement for the sake of others, and the quantities are not even close to comparable. While the joy you can find through improvement for self-benefit is very limited, the joy available to you through improvement for others is unlimited. The cause of other people can absorb any sacrifice you give for it, up to and including all things.
The joy you feel in self-improvement for your own sake is obviously limited to yourself. When you become willing to rejoice in the joy of others, the domain of what you can receive through your sacrifice extends through all people, in a chain as infinite as the relationships between all people, through all time.
How much joy you experience will be determined by how much responsibility you willingly take upon yourself. The more you assume responsibility for the benefit of others, the more reasons you will have to become the best person you can possibly be, the more meaning you will find in your life, and the more joy you will experience as you grow into your full potential.