I believe I see signs in numbers sometimes. Most of the time it is very meaningful and accurate. I do look for those, especially if I am planning something important.

However, I do not take it to be an exact science. If I get a bad sign I chose to do what I planned anyways, because I know that I can't trust the signs 100%.

When I was in labor for example, on the way to a hospital I saw very bad number combination. Couldn't back out from having a baby, so chose not to pay attention. Everything went well

I think it depends a lot on how you use your signs, if you retain some critical thinking about them and use them to your advantage, and they don't stop you from leading normal life, it shouldn't be a problem.

As for the ancient times, there were people considered insane then as well. Not all of the psychotic sufferers were regarded as gifted with insight.