I stumbled upon a funny looking mushroom somewhere in the middle of Finland a few summers ago.

Well, now you know that this is a good one. But of course, it's the case where you want to have someone knowledgeable with you if you don't know much. In most cases it's easy, but there are kinds of "bad" mushrooms which look like the good stuff. So I'm checking references and a nice "picture mushroom" app, but in case of any doubt it's easy to just keep going. (and the app is saying exactly that you don't want to make ANY decisions based on its results)