If evolution is true... (not an anti-evolution topic)

If evolution is true (e.g. natural selection, and all that) then why did humanity evolve to have concious thought?
It should be clear that we have become a dominant feature of this planet (at least.... that's what we have been lead to believe...) because we are smart, have thumbs, can use technology. Well that's nice and all, I mean, I certainly am glad we can use this technology, that I have a thumb, and that I can think conciously (i'm not saying that all animals can't, but what scientists tell us is that we are smarter than them). Why did we evolve like this? What set us apart from the other primates that we could survive better?

For example, perhaps the first homo sapien found that he could make a rock sharper by applying another rock to it, to make a pointy rock. This primate could now succesfully break into a coconut easier (or, into the skull of thine enemy), but does technology = better concious thought?

I am finding every day that we rely on concious thought more than any other means of survival (i don't think we even really use our nails that often other than to maybe open a pop can), i mean, we don't even need our teeth, because we can feed ourselves intraveinously, hell, we can keep a vegetable'd human alive through IV and oxygen mask methods.

I know, you're thinking man, this guys stupid. Well, ****, I agree. But I'd rather be stupid and realize that we are too reliant on our brains than be smart and relinquish all control of my body to a brain that can be tricked and fooled into believing it needs things it doesn't. (I'm sure you can make your own conclusion from this...)