In the summer of 2010, Cassius Clay met Kanye West during a shopping trip at Barneys New York. Kanye complimented his velvet Stubbs & Wootton slippers, which featured jousting knights on the top of the foot. The two talked about the slippers, and Alber Elbaz’s and Lucas Ossendrijver’s designs for Lanvin. Eventually, they exchanged email addresses. Kanye didn’t have a cell phone at the time.

A few weeks later, they ran into each other again, this time in SoHo. At the end of August, Cassius, who had just started his sophomore year at Yale, received an email from Kanye asking if he was interested in working for him as a junior creative consultant. Cassius was torn. “I was weighing what was a very real disruption to what I’d spent my entire life trying to do. To get into Yale, and earn my degree.” He told me this over the phone, in his first interview since 2010. He decided to take a year off from Yale, and at Kanye’s request, Cassius moved to New York the following day. “It was hard for me to come up”—he sighs and pauses—“with reasons not to do it.”

For the next three months, Cassius researched paintings, sculptures, photographs, and designers that would be used as references for stage designs, videos, merchandise, and other visuals for the release of Kanye’s fifth studio album My Beautiful Dark Twisted Fantasy. Occasionally, he also assisted in styling the rapper for performances and appearances.

Kanye welcomed Cassius into his coterie of collaborators and friends. Cassius sat in on studio recording sessions for MBDTF. He even received a special shout out from Kanye, who tweeted after his Saturday Night Live performance in October 2010: “The art and style team, Virgil Abloh, Lauren Matos & Cassius Clay.”

But in December 2010, a month after the release of MBDTF—an album critics refer to as Kanye’s best and key to the rapper’s redemption—and just as Kanye began working on the Watch The Throne album with Jay Z, Cassius walked away from all of it. From the once-in-a-lifetime job. From the hottest rapper alive.

He could’ve had it all. So, why’d he give it up?