What You Know For Sure That Just Ain't So

It ain't what you don't know that gets you into trouble.
It's what you know for sure that just ain't so.

- Mark Twain (attributed)

If you would be a real seeker after truth,

it is necessary that at least once in your life you doubt,
as far as possible, all things.

- Rene Descartes

The more opinions you have, the less you see.
- Wim Wenders

About most subjects, there is not "The Truth."
There is merely one's personal truth.
- Jonathan Lockwood Huie

The problem with making assumptions
is that we believe they are the truth
- don Miguel Ruiz

Examine, inquire.
Look into the nature of things.
Search out the grounds of your opinions,
the for and against.
Know why you believe, understand what you believe,
and possess a reason for the faith that is in you.

- Frances Wright

Everything is not as it appears to be.
- Proverb

People are dumb, panicky dangerous animals and you know it. Fifteen hundred years ago everybody knew the Earth was the center of the universe. Five hundred years ago, everybody knew the Earth was flat, and fifteen minutes ago, you knew that humans were alone on this planet. Imagine what you'll know tomorrow.
- 1997 Comedy Movie "Men In Black"

Further reading: Question Your Questions

The Illusion of Knowledge

Maybe So, Maybe Not.

Expectations

Truth isn't True

Assumptions