"No one was ever quite like you. The Lord made only one, without carbons. You are not repeated and not repeatable. The chance of there ever being someone identical to you must be compared to a number so high it doesn't even have a name; it would have to be written as a 1 followed by 9,031 zeros.
"No one else can do what the Lord sent you to mortality to do. The value of what you have to contribute will come through the expression of your own personality, that particular spark of the divine that makes you unique, setting you off from every other living creature. The mark you leave on the world, on the hearts and minds of others is as distinct as your thumbprint."
From Learn, Then Serve, a 1980 Relief Society booklet