Most often school dreams are connected to a particular issue at your job or in your career because school is your first job and where you learn the dynamics of the work force: being on time, being prepared (having done your home work), being tested and judged, wanting to succeed and move on up to the next level.
Compare the stress in your dream to what is going on in your job or career and you are likely going to be able to make the connection. For example, dreaming you have to take an entire year or even a semester all over again even though you know you already graduated may mean that somewhere in your job or career you having to prove yourself all over again even though you know you’ve got what it takes.
It can also mean that it’s time to learn a lesson or educate yourself on certain matters. You may be feeling tested or that you need to pass a particular situation with flying colors. Do you have a fear of failure? If searching for a class you are directionless in some area of your life. If you are late for class you are afraid of missing an opportunity or are feeling unprepared.