An intense storm drenched San Diego, California this week, causing flooding across the county.

That didn’t stop Kenneth Barrese, a math instructor at the University of California at San Diego, from continuing his lesson on vectors and vectors in 3D in Peterson Hall.

In Reddit’s WTF community, redditor HannibalofBarca posted this image of the unruffled teacher who chose to endure socks of mush in the name of calculus. Other redditors who happened to be sitting in the class mentioned that only about half of the students showed up that day due to the storm, but of those who did, most stayed even as the lecture hall started flooding. You can thank them later for ruining the grading curve.

Here’s a clip of the scene, posted by redditor Spontaneity8 in Reddit’s Gif community.

Some people felt the instructor made a dangerous choice.

Others acknowledged the man’s perseverance.

See the full Reddit discussion here.