Yesterday I got confirmation that sometimes it's better to forget some of them, or rather never use them.
One of the most dangerous is certainly 'typisch', that means 'typical.' Never use the word 'typical' when it comes to another culture. You will not get anything good. Even if what you're saying is actually typical.
ps. I'm back. Sorry if I have not updated the blog for a while. Sometimes 24 hours a day are not enough.
How I'm learning German