It is so easy to think that you know everything about a situation, especially if you have researched and really looked into every detail. However, you should know that not everything is what it seems and this simple fact will shock you throughout your life. Just when you think that you have everything in control you will find that it can easily be ripped away from you. Just know that it is completely normal, and nobody has a full grasp on everything in their life. There are people and situations that can completely deceive you, and leave you looking like you didn't know anything.
Don't be too hard on yourself when situations don't work out for the best, because this same logic can be applied in reverse. What seems like it could be a bad situation can actually turn out to be a lot of good. Just enter into everything that you do with your eyes wide open, and expect the unexpected.