Is everything really a competition? then why do humans seem to scuffle over any and everything, even the smallest of things?

Yes there are people that do this. But not everyone .

  Weak minded people do,this 

It really is. Its dog eat dog. Kill or be killed. We are no more than animals working to survive the next breath.

If there is widespread poor health in a society, people might easily get the idea that that level of health is the norm for human beings. They might not have a good idea of what true health is. But that doesn't mean that true health isn't possible. It's a matter of discerning the causes of poor health that exist in that society and then eradicating them.

Same thing with what you're talking about. Most adults act that way, so you think that's just the way humans are. But it isn't so. It's possible for us to learn to live another way if we choose to.

What make humans different from other animals is the frontal lobe. It is the newest part of the brain. Our subconscious still exist in the savannahs while we live in concrete jungles. Thats why humans do as humans do.