Wisdom

“The pen is mightier than the sword”

The exact phrasing dates to 1839, but "the idea of communication surpassing violence in efficacy had numerous predecessors" -- wikipedia.

"don't make promises you can't keep"

Calibration of this advice.

"happy wife, happy life"

If you're in a good place in your relationship, you may be more compelled to treat your husband amazingly—from telling him how sexy he looks in the morning to giving him a back rub after a long day—thus boosting his quality of life -- womenshealthmag.com.

"out of sight, out of mind"

When something is not nearby, it is forgotten about -- wikitionary.

"You may be disappointed if you fail, but you are doomed if you don’t try"

Attributed to Beverly Sills. By request.

"the whole is greater than the sum of its parts"

The level of realization of this truth.

"There is no elevator to success. You have to take the stairs."

Attributed to motivational speaker Zig Ziglar.

"easy come, easy go"

The phrase can be used consolingly after a loss, implying that since the gain was effortless, the loss isn't a significant matter -- Brave AI.

"do the job but be willing to let it go"

Calibration of this statement.

"I think, therefore I am"

Calibrated at 400 in Truth vs. Falsehood.

misery loves company

People who are unhappy may get some consolation from knowing that others are unhappy too -- dictionary.com.

“Keep calm and carry on”

Slogan that appeared on a motivational poster produced by the Government of the United Kingdom in 1939 in preparation for World War II -- wikipedia.

"time is of the essence"

Said when something must be done immediately -- dictionary.com.

silence is consent

Request: The idea that if you don't disagree, you automatically agree. Keeping quiet is the same as giving permission.

"haste makes waste"

Acting too quickly may actually slow things down -- dictionary.com.