What these things have in common, of course, is that none of them is true. July 2011 will have 5 Fridays, 5 Saturdays and 5 Sundays, but so will July 2016. I'm not great at math, but I'm fairly confident that's not 823 years.
The Great Wall of China is long, but not particularly wide (as far as manmade structures go). It is approximately the same color as the land that surrounds it. Continually improving technology allows such things to be seen from space, but there are many other structures that men have built which are more easily observed.
And the myth about 10 percent of our brain? No one really knows how that belief began, but it's been repeated so often that most people accept it as true. Neurosurgeons are not among them, which explains why they carefully plan each incision they will make when performing brain surgery.
Just because "everybody knows" something, that something isn't necessarily true. Common sense isn't as common as we might like to think. Stories are created, repeated and exaggerated. After a while it's hard to distinguish between rumors, myths, outright lies, and the truth.
It was Jesus who said, "And ye shall know the truth, and the truth shall make you free" (John 8:32). The problem is, we don't always know where to find that liberating truth. Fortunately, Jesus also gave us the answer to that. While praying for his disciples one night, he asked that God: "Sanctify them in the truth; your word is truth" (John 17:17).
The truth is found in God's Word, the Bible. While that e-mail Grandma forwarded to you may or may not be true, we know that God's Word is truth. Your best friend's Facebook status will sometimes lead you astray, but the words of the Bible will lead you to freedom.
Read the Bible. Study God's Word. Know the truth.