Do adult children owe their parents lives after taking care of them for 18 years?

I feel like we do owe it to them because they took care of us, spend a LOT of money on us, fed us, clothed us, took us to doctors appointments, put us in school and everything so we DO owe them. If my parents need help or need some money I’ll be gladly to do it because they took care of my sister and I so we owe them for that but we don’t owe them EVERYTHING.