Impure behavior

One of my friend, M said to me in his text message: Impure motive make excellent results in every cases. It was the fresh view-point for me.

The persons who try to be musicians for being popular with girls/boys, The persons who aim to become doctor for money, etc...these are impure with my definition. I had despised somewhat such the persons, just because. What is more, I didn't accept various impure behavior as human being, not just impure motive, such as sexual desire, eating appetite, laziness, irresistible, dependence, unkind ...everything!! I'm confusing and I cannot recognize what is pure or impure anymore. There are many prohibited points and it makes me stifling. 

After I read his message, I wondered if I try to accept somehow impure behavior. When I think well about it, I sometimes want to be lazy/unkind and allow to have various desires naturally as human. It’s not spoil myself, just accept who I truly am.