To be a person is to be in debt. Humanly, we owe our existence not only to our parents, but to generations upon generations. For many years, each of us, no matter how well endowed with health and talent, lives in a state of total dependence on the help of others—others we can't really hope to compensate in this life. Rather, we repay them (and God) by doing similarly for others.
To be born in freedom is to owe a special debt—a debt of gratitude to those who have sacrificed for us. Maybe they've died or sustained terrible injuries in war. Maybe they've lost husbands or sons or daughters. Maybe they've spent fortunes, or been imprisoned. Maybe they've let go of comfort and security and familiarity to start fresh in a foreign place.
The bounty of our lives comes from their deprivations. We should never forget that.
Only a few of us may be called to make a similar sacrifice, but all of us are called to "make a return" of gratitude and sacrificial offerings. Conscious gestures of recognition of our essential reliance on others known and unknown, including those who have died humble and humanize us.
Other cultures are or have been better about realizing this than our present one. Let's try to fix that.