All of the animals except for the man know that the principle bussiness of life.

u are right human mind is not satisfied with what u have .this is the reason many suffer in life .everyone knows but we don't follow it.

That's what differentiate us from the animals. We have thinking brains so we think a lot. Animals have brains but they don't think, they use their brains to do everything instinctively. We have instincts too, but because we have thinking brains we tend to seive and calculate everything before we act so that we do not involve in dangerous or jeorpadizing circumstances. Yeah, human beings do not enjoy all the time. But we still can find time to enjoy. Some people say, we work hard, then we play hard. What you say is true, many of us do not enjoy enough and we are wasting our time worrying. But that's the nature of human beings and we have to be content with what we are made of. The best thing to do is to think positive about everything, and from there we can achieve an inner peace and tranquility. God bless you.

That is why we are human, we have fellings. We have to straggle to maintanin our lifes, to make a better living, to have much money to do what we likes, to make our friends, family, husband/wife happy. It is that responsibility that build up our society. Also, I donnot think your feelings about amimals are right, bynow we donot know the thought of amimals even dogs--the best friends of human. Maybe the amimals also have their own problems, but we couldn't know. Do not feel impressed by the life, life is colourful and enjoy it.