Prophesying was the only human art that couldn't be improved by practice.

数学不是观赏性运动，你必须参与其中才能理解。

And we also suck in messages from everything from the television, to advertising, to marketing, etc. These are hugely powerful forces that define what we want and how we view ourselves. When we're told that banking is a very respectable profession, a lot of us want to go into banking. When banking is no longer so respectable, we lose interest in banking. We are highly open to suggestion.