What are the top 5 essential problems for a physicist to understand and solve?

[Kabbotta]

I wanted to hear suggestions for the...roughly...5 most essential physical problems that a serious working physicist should understand how to solve. Like the conceptual goals for someone who is just getting into the center of my study of physics (headed towards graduate school in a year.) Thanks for any help. This forum has been a massive help in general.

 

[tom.stoer]

Do you mean essential problems in current research programs or in education? I guess the latter one.