I was reminded of two quotes, neither of which I can accurately attribute:

It infuriates me that you cannot accept that I am right.

A learned fool is more foolish than an ignorant one.

And a few which can be attributed:

Modern liberalism "equates democracy with [its own] strand of liberalism--[theirs alone being neutral and permissive--by compelling] others to shut-up or disappear."
Jean Bethke Elshtain (paraphrased)

"Believe those who are seeking the truth; doubt those who find it."
Andre Gide

"Show me a thoroughly satisfied man and I will show you a failure."
Thomas Edison

And, finally:

"In theory there is no difference between theory and practice. But in practice there is."
Yogi Berra