こういう大事なことを知らないのを、むしろ自慢にしている人もある。の英語

Some people are rather proud of being ignorant of such an important matter.

It is no use pretending you know nothing about it.

If you are ignorant of what you ought to know, you will look foolish in company.

But that's only natural because you don't know their ways yet.

details known by only a few highly placed persons

It's better for you to keep out of private affairs.

Wet blankets are not always unpleasant after you get to know them.

A wet blanket is not always unpleasant when you come to know him well.

Don't be so selfish; you're not the only pebble on the beach.

If he has a particle of common sense,―a grain of common sense,―he will not act so foolishly.

It is important to sometimes listen to others' points of view instead of being so insistent of your own.

Only a handful of people know the fact.

One is apt to think oneself faultless. State the facts as they are.

Why don't you mind your own business? What do you gain by sticking your nose into other people's affairs?

One is apt to think oneself faultless. State the facts as they are.

You have good reason to suspect us,―It is true appearances are against us,―but we are innocent.

It is a pity that a man of your ability should remain unknown to the world.

I talk to myself a lot, but there's no need to worry.

People that look fair are sometimes not fair at all.

You're bound to feel that way at first, I guess.

It's reasonable that you feel that way at first.

Where ignorance is bliss, 'tis folly to be wise.

I need not mention such a patent fact―such a palpable fact―such a glaring fact.

Who doesn't know such a simple proverb?

I don't like to carry out things exactly as I'm told.

It's well said that "You can't judge people by their appearance", isn't it?

to know something superficially rather than deeply

of a person, pretending not to know something even though she or he does know it, because knowing it is inconvenient

One shouldn't criticize someone merely on hearsay [on someone else's say‐so].

You don't know when you're well off.