Antiquated Thinking

Who decides what counts as antiquated thinking? Who decides that it is antiquated, not classic? Maybe it doesn't matter until it affects someone personally. Antiquated thinking began sometime before the present, although it doesn't really matter how much time passed in between the original idea and the present. Sometimes, thinking becomes antiquated in a matter of minutes, as opposed to the idea of independence, for one, which will never go out. Everybody wanted independence in 1776 and they still want it now--but I digress.
How do we know that thinking is old? Maybe it's more of a subjective thing. Take the Bible. God created the heavens and the earth. We all know that. Some people say that thinking is antiquated, but it will never be in my book, at least to the extent that I'm discussing antiquated thinking--thoughts that are due for a change.
For an example of antiquated thinking, I will use something silly. Back in the day, at my high school, people couldn't wear jeans to classes. They had to wear dresses--women, not men. ^_^ The school board decided the thinking was antiquated, or they would not have started allowing women and men to wear jeans to class.
That's fine until we get to more difficult issues. I'm being vague, I know. I just thought it was an interesting topic. I conclude that thinking becomes antiquated when people decide it is antiquated, and there is a majority vote.
So where do we draw the line between stubbornly sticking to antiquated thinking and being brave enough to stick to your guns? Isn't it only between the person and God? God is the one who knows the motives and intentions of the person, right? And if a person can honestly say they're opening up their mind to be filled with God's spirit, should he be condemned for sticking to his prior thoughts?
Just a (antiquated) thought...thanx for listening!