Well, according to a story on the Telegraph, the average person's happiness curve looks U-shaped.

根据一个《每日电讯报》的故事，平均每个人地幸福曲线呈u型。

youdao

Many environmental problems get worse as a country first industrializes, but once it reaches a certain level of income, the trend often reverses, producing a curve shaped like an upside-down U.

当一个国家刚刚开始工业化进程的时候，许多环境问题会恶化，但是一旦这个国家达到一定的收入水平，环境恶化的趋势就会反转，从而得出了一个被称为“Kuznets曲线”的倒U字形的曲线。

youdao

The relationship between the insulin secretion and elevated fasting glucose showed an inverted U shaped curve.

空腹血糖浓度与血浆胰岛素分泌水平表现为一条倒U字型曲线。

youdao

As it turns out, they also have a distinctive U-shaped curve, and it looks a lot like ours.

FORBES: Study: Humans Aren't the Only Apes that Have a Midlife Crisis

Taken altogether, these pressures drop us to the bottom of the U in the U-shaped curve of happiness.

FORBES: Study: Humans Aren't the Only Apes that Have a Midlife Crisis

Calabrese says that many poisons follow, instead, a U-shaped curve: The death rate goes down as the dose climbs from zero to a certain small amount, what you could call the optimal exposure.

FORBES: A Pinch of Poison