Others have talked very well about the concept of self, so I won't. I just wanted to add that we feel like there should be some meaning to our lives, make an impact that will be remembered for a long time. Sure, fine things to pursue but it's good to do so dispassionately keeping in mind that far greater achievers are not generally remembered. From the top of mind, I don't know who invented the safety pin or stickers or tshirts or ruled notebooks.
I take comfort in participating in this huge system of life and death and in knowing that billions have lived ordinary lives and died. I don't dye my hair and don't ignore signs of aging. I'm happy to grow older and retire and reduce my needs and spend more time with friends and family and when I die I'll join the legion of billions of decent, hardworking, perfectly ordinary people. It's a fine group to be part of.
* obstinate: same responses/approach even when presented with new information
* persistent: updated responses/approach when presented with new information