Why did the sun not go to college?

Why did the sun not go to college?
Because he already had a million degrees

This is a pun. The word degrees has multiple meanings. Two of them are an academic rank gained by completing schooling, and a measure of temperature.

Depending on which unit of temperature you are using to measure the heat of the sun, and which part of the sun you are measuring the heat of, the sun could be one million degrees, so that part of the joke checks out, it's just that having temperature degrees won't get you a job.

Kids: you should still go to college even if you have multiple temperature degrees.