Missing any math in any year is a disaster. There is a real continuity in math teaching starting from addition through high school. I've seen so many people who gave up early on, and they have _no hope_ of making it up later on.
It was really frustrating for everyone. I just wasn't in a position to basically teach them a few years of high school math from zero foundation.
And you'll see the same pattern in pretty much any of the books written over the years about the challenges the author faced in the first year of their MBA program.