I am trying to hear what others are doing, looking for a "spark" for myself.
Although spiritually everyone matters (according to my spiritual/religious beliefs), there are ways to make a positive impact on the big picture of humanity, where you would actively matter.
I've been a volunteer catechist to 5th graders in our parochial school for 9 years. Along with teaching church doctrine, I work hard to teach the kids the value of life and to be kind at every opportunity. In that way I fel I matter.
I also worked for many years in a nursing/rehab home doing sensory therapy, and the key way to take that extra step and focus on how important they are even though they're confined to their beds or to comfort someone with dementia who's having an anxious day. In that way I matter.
Not everyone has the time to commit to volunteerism, and not everyone has a job that gives them opportunity to deal directly with someone's fragile emotions, BUT unless you live alone on an island, everyone can do something daily to make a positive difference to humanity.
A big thing for me is to simply talk to people. A "hi, how are you" to the bank teller, saying "thank you" to the community service people picking up trash in the parks, letting the guy with two items in his hand go ahead of you on the grocery line when you have a cartload of groceries, wave or give a thumbs up to the firefightersas they pass by...things like that. Because it makes them feel like THEY matter, and that's priceless.
It's great if on your tombstone it can be written "She cured cancer and saved millions of lives", but it's equally great to have written "She was kind to strangers". Our daily behavior impacts others in ways we don't even realize.
To the poster who said he doesn't owe the world anything, maybe so, but isn't it a good thing to do good of your own free will?