When you invest your time, you make a goal and a decision of something that you want to accomplish. Whether it’s make good grades in school, be a good athlete, be a good person, go down and do some community service and help somebody who’s in need, whatever it is you choose to do, you’re investing your time in that.
Being in a community, from a scientific perspective, we are constituted so that simple acts of kindness, such as giving to charity or expressing gratitude, have a positive effect on our long-term moods. The key to the happy life, it seems, is the good life: a life with sustained relationships, challenging work, and connections to community.
Every successful individual knows that his or her achievement depends on a community of people working together.