In other words, in the absence of a neural mechanism that generates unrealistic optimism, it is possible all humans would be mildly depressed.

换句话说，如果没有产生非现实主义的乐观精神的神经机制，可能所有人类都会患有中度忧郁。

youdao

The fact that we do is probably a result of an unrealistic level of optimism about how much we will expect to like others.

这可能是因为我们总是抱着很不现实的乐观期望去喜欢他人。

youdao

The bad kind of optimism (because it's so unrealistic) is that many in Silicon Valley think another IPO boom is around the corner.

FORBES: Silicon Valley's Future