The layperson cannot really understand mental illness.

外行不完全了解精神病。

《牛津词典》

In my experience , very few people really understand the problem.

据我的经验看，真正理解这个问题的人很少。

《牛津词典》

I do not really understand him.

我不是很懂他。

youdao

To really understand this art you have to see it in its environment.

VOA: special.2009.04.08

So this is important, it's a little bit subtle, but if you don't really understand this deeply, you'll find yourself getting confused a lot.

但你如果没有挺深刻的理解，这件事的话，你会发现自己在这个问题上很困惑。

麻省理工公开课 - 计算机科学及编程导论课程节选

If you want to really understand this in a practical sense, it's more as though these guys are hired hands.

用更现代点的观点来解读,他们更像是雇农

耶鲁公开课 - 古希腊历史简介课程节选

But even those who believe Pinterest is onto something big may not really understand why.

FORBES: Pinterest's Obvious Secret

Lots of scientific firsts are things that the average person can't repeat, or even really understand.

FORBES: All Mapped Out

We are bringing the latest in applied psychology and letting people really understand themselves better.

BBC: Taking Sandhurst to the DR Congo