Not every adult is sad about losing something, but I was very upset about losing my wallet.

不是每个成年人都会因为丢东西而难过，但我丢了钱包很难过。

youdao

I believe this was a perfect lesson for a child in losing something important...to lose it and feel the full weight of that loss, and then to miraculously get it back.

我相信这是一个完美的教训，对于一个孩子来说，失去重要的东西……失去它，感受到失去的全部重量，然后奇迹般地找回它。

youdao

All's I'm saying is I'm losing something too, said Father Terry.

我的意思不过是说，我也同样要失去一些东西了。特里神甫说。

youdao

This means you should not risk losing something you have by trying to get more of something you do not have.

VOA: special.2010.06.13

Or losing the ability to do something.

VOA: special.2009.10.25

This is presidential historian and author Robert Dallek: "Once the public turns against a war, once it is convinced that you are embarked upon if not a losing enterprise then something that is going to produce a quagmire, it creates tremendous political difficulties for the president and it undermines his credibility, trust in his judgment and his ability to put across his domestic reforms,"

VOA: standard.2009.10.09

Sometimes losing something makes us appreciate it more when we get it back.

FORBES: Michael Vick's Redemption

Jeff Duncan, spokesman for the Save the Scottish Regiments Campaign, said Scotland was losing something very important for no good reason.

BBC: NEWS | UK | Scotland | Army regiments merger goes ahead

The basic principle at work here is loss aversion: the idea that losing something has a stronger emotional impact than gaining something of the same value.

WSJ: Dan Ariely on House Sales and Netflix | Ask Ariely