Is Harvard Math 55 real?

Have you heard of the Harvard Math 55 course? It's supposedly a legendary course known for its rigor and difficulty. But is it really as intense as people say? I've heard stories of students spending countless hours studying and still barely passing. And I've also heard that only the most talented math students are even allowed to enroll. So, is Harvard Math 55 really a thing, or is it just a myth that's been exaggerated over time? I'm curious to know the truth behind this legendary course.