I did not know that the word Cacophony is pronounced:
Up until today I pronounced it: Kako-Phoney.

Whenever I discover that I've mispronounced a word, I get embarrassed.
I know that the embarrassment comes from my ego.
I associate mispronouncing words or grammatical errors with being not very bright.
This is a flawed way of thinking--as linguistic intelligence is only one part of the multiple intelligence theory.  Not to mention often times, it is a matter of accents and regional variations. Throw in mother tongue and intonations, one must realize that this is not a good measure of intelligence.

When I stop being critical of other people's grammar and/or manner  of speech,
then I will cease to be afraid of making mistakes of my own.
Much more learning happens when we keep ourselves open.
In short, we learn faster and better in the absence of ego.
Not just in language but in life.