A person that have it easy to learn but don't take the time to do it.
You are such a Vilhelm, if you would oly take the time to do your homework.
A guy who seems cool and chill at first but, as time passes he gets more and more arrogant and he thinks that he can do no wrong and everything is everyone else's fault.
Person 1: Heard of that guy named Vilhelm, he seems kinda cool.
Person 2: Yeah but he is a huge dick and can't take a joke.