A friend of mine asked me that question on my birthday fifteen years ago.
I asked that I just play my own role, me, susi.
And then she replied that my answer is wrong. She asked me to think again.
But I given up at that time and I asked her to reply her own question. :)
Then she said that i have many roles that i have to play well and sincerely.
She made a list :
1. I am as a woman
2. I am as a daughter
3. I am as a student
4. I am as a friend
5. I am as a sister
6. I am as .... atc.
And then the last She asked me, "did you do those roles well?"
That's the point.
I always remember her question, as I always remember her as my best friend.