I was given to you soon after you were born

I am a little which distinguishes you from others. Every one has me. I am neither a substance nor a common noun. I was given to you soon after you were born. Of course, you have soon after you were born. Of course, you have me now. You may be inconvenient to get along with your family, friends and others if you don't have me. And also, it would not be easy for you to make yourself known to others. There is a saying that a tiger, after his death, leaves his hide, and man leaves me. Whether your name live long or not depends on what you have done for others.



What am I ?