What took you longer to understand: good news being priced in, or bad news still leading to a rally?

One thing that took me a while to internalize is that markets do not react to news in isolation. They react to the gap between the news and what was already expected.

That is why a company can post good numbers and still fall, while a mediocre result can sometimes send the stock up.

For those who have been in the market longer, what took you longer to really accept: good news already being priced in, or the fact that bad looking news can still lead to a rally?