The people who raised you worked hard for your chances. Your character is how you say thanks.

Somebody spent hours you never saw so your options would be wider than theirs. Paying that back in money or achievement is not really available, and it was never the point. What lands instead is how you carry yourself when nobody is watching, because that is the thing they were trying to build. Gratitude that lives in behaviour outlasts gratitude that lives in words.

If they are around, name one concrete thing you know they gave up. If they are not, the same principle holds anyway. Live in a way that would make the trade look worth making.