"Knowing is knowing, not knowing is not knowing, just knowing." Meaning: What you know is what you know, and what you don't know is what you don't know. This is the wisest. Read the last word "knowledge" four times, just like "wisdom". )
"Let bygones be bygones" means: Let bygones be bygones.
"Dead wood cannot be carved" means dead wood cannot be carved.
"Don't be ashamed to ask questions" means: Don't be ashamed to ask questions from people who are not as good as yourself.
"Eat without words, sleep without words." Meaning: Don't talk while eating and don't talk while sleeping.
Hehe, there are many more.