Think about the times you have helped a friend achieve their goal. You may have run a few miles with them each day in preparation for a 10k. You might have stayed up late at night reviewing flashcards for a big test the next day. Or, maybe you watched a family's children for a couple of days to allow the parents to work on their goal of opening a new business. These types of scenarios work great to answer this question. Simply tell the interviewer a high-level overview of your scenario, and share how thankful the individual was for your contribution.