Stop Keeping Score

I woke up at 4:07am to bring a couple of friends to the airport. They were headed to Colorado and booked an early flight to maximize the amount of time spent with family. As they got out of the car, they thanked me for the ride as though I had done something extraordinary. Although I went to bed early and got plenty of sleep, I could sense a feeling of “we owe you.”

I love to fly and often need rides to/from the airport. Whenever one of my friends goes out of their way to cater to my needs, I have the same feeling of “I owe you.” 

What would happen if we sacrificed for our friends, expecting nothing in return?

What would happen if we stopped keeping score?