Mohit Mamoria wrote  Are You Who You Think You Are. I think it's pretty bang on article to make that enquiry into who we are, not by definition of our jobs. 

A wise man asks three bricklayers what they are doing. One says, “I am laying bricks.” Another says, “I am building a wall.” The third one says, “I am building the cathedral.”

Also from the article my favourite quote of all time: 

“Today you are You, that is truer than true. There is no one alive who is Youer than You.” ― Dr. Seuss

And this beautiful gem: 

You are a story, yet to unfold,
You are a book, yet to be told,
You are a pot, before it’s mould,
You might be just a rock perhaps,
Just a rock? Yes, but a rock of gold.

I'm going to be making that very same enquiry into myself over the last year of my 20's. Yesterday I turned 29 and will be writing some memoirs of the last three decades and plans for the future over the coming weeks and months as we close 2017.