I realized that life is not always fair with you. But however cruel it is, be firm with your principles. Know yourself and ignore the discrimination by others. I read this in my teenage year, the time in life which makes you, and the values of Karna become my values.
I was so impressed by this book, that some year later, in my college days, I read another book by same author on Krishna's life named Yugandhar (roughly meaning emperor of Era). Now every time I am in tricky situation, I always think what will Krishna do in this situation.