Hardship builds moral character.

Alternative form of what you lose on the swings you gain on the roundabouts

(UK) There are both gains and losses in life; you win some, you lose some.

Alternative form of one's got to do what one's got to do

If one does not know about a problem or a misdeed, one will not be able to render oneself unhappy by worrying about it; often used to justify not informing an individual about a problem or misdeed.

What you said is so wrong it reveals you lack basic understanding of the subject or relevant experience.

People tend to take things for granted while they are available.

Two parts of an organization are unaware of each other's activities.

Problems and losses that do not reach the attention cause no worries and no grief.

Do not procrastinate whatever that can be done today until tomorrow.