This is an excellent analogy! Giving blood for 60 years. Saving one life at a time, and then how many more lives do those lives save? That’s the key to “my purpose”. You mentioned high peer pressure for doing something significant. One of my more frequent questions when I see genius in action is, “What can I do that’s that great?” It doesn’t have to be great! It can be consistent. Give a little blood (life) every day. Do small, great things. Constantly be on the alert for how you can help someone, something now.