Once a habit is formed, it's difficult or even impossible to change or get rid of it.

一旦习惯养成就很难甚至不可能改变或者戒除。

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Once a habit is formed, it is difficult and sometimes almost impossible to get rid of it.

一旦习惯形成，要想摆脱它，那几乎是不可能的。

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But once you put it on autopilot, once a habit is firmly established, you don't really have to focus on it much.

一旦你的事情水到渠成，一旦习惯稳定地形成，你就不用再过多地关注它。

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And sometimes what was once a beneficial habit continues even though it no longer benefits us.

FORBES: Could We One Day Switch Off Bad Habits in Our Brains?

An adjective habit, or a wordy, diffuse, flowery habit, once fastened upon a person, is as hard to get rid of as any other vice.

FORBES: Mark Twain On Writing: "Kill Your Adjectives"

And the costs and revenues of once-separate businesses have a nasty habit of getting tangled up, which makes it more difficult to judge the true profitability of each.

ECONOMIST: It��s got to fit somehow