Some users tend to answer their own question and mark the answer as the correct one. For clarification, this is when there are already one or more answers given to the question. I've marked an answer on my own questions as well, when I found a solution and no answers (or useful ones) were given. Like this:
I've seen it a couple of times now on StackOverflow but I didn't pay much attention to it as I don't know the reason behind it. Sometimes the given answers were not directly the anwer to the question but they were helpful for the user to get to the solution. So when a user then answers his own question (with enough detail to the final solution) and marks his answer as the answer, this makes sense to me.
I don't do this as I want to 'reward' the person who got me on the way, for example:
But I got a bit frustrated by a user who accepted my answer as the answer to his question only to find out that later on, he answered his own question and marking his as the correct answer. Plus, his answer was almost completely based on my answer, in which I put an amount of effort to provide every bit of info he could use. Reference:
I'm not in here for the rep but others and I tried helping him. And when I pointed this out to him, all I get is: 'thanks all, I found the solution'.
Is this normal behavior or am I overreacting here?