to play the devil's advocate: o que isso significa?

I know many of us foreign language students dream of one day visiting or even living in a country that speaks the target language. Let's suppose one day, some of your classmates from your English school start planning on backpacking through Europe without any backup plan or even that much of money. You're excited to visit Europe and get the chance to put your English into practice, but you put forward objections to that idea so they'll think about it more carefully. So you say: I don't mean to ruin our plans or anything, but let me play the devil's advocate. I think there's a lot at stake here and we should think about it very carefully before making any decision.

When you play the devil's advocate, you say arguments against ideas or plans so people will discuss them more carefully. It's like you're being against them, but what you're really trying to do is to make sure there will be no flaws in a given plan. After all, if you discuss things that may go wrong before they happen, you make chances of things going wrong very low. So tell me about your own stories. Are you someone very rational that's always playing devil's advocate or you let things happen without thinking too much about them? Leave your answers in the comment section. Take care!