Time?

No, not the Pink Floyd song... What's time, really? Does it actually even exist? I think that maybe time is just something humans came up with to not be driven insane. The reason we can't time travel is because our minds can't comprehend NOT having time. Time might happen "all at once", but if this theory is correct, then it wouldn't technically be "all at once", this being a construction of time... ANYWAYS, back on topic. Humans can't actually comprehend "the beginning". Try it. Even with religion, we can't actually specify what this "beginning" is: "In the beginning, God created.." (not accurate quote, don't get on me about it.) Yeah, and...? When is this "beginning"? We can think about our beginning, when we were born, we can think of the beginning of events, the beginning of wars, but not THE beginning of TIME. So, does this prove that time doesn't exist? If it doesn't, I still think we can't comprehend it. How do you break down barriers that strong, there from birth? If time happens all at once, then "time-travel" is actually possible, in a sense. If we break down the barriers in our minds, if this theory is correct, then time is just a complicated illusion we set up to keep ourselves sane. With everything happening at once, our minds couldn't take it. Hmm... Maybe this is absolutely insane, and I'm probably writing to no one, but here it is. Possibly too far-fetched for it to be true, but eh...