After going missing under mysterious circumstances, a Penn State University (PSU) student turned up safely in the same manner.

According to the Associated Press, Jon Steindorf, 23, was not at his off-campus apartment on Friday when his parents came to pick him up for his commencement ceremony. The family found out their son not only was not graduating, but was not enrolled in classes last fall, which he said was supposed to be his final semester.

No one had seen or heard from Steindorf since earlier that day and he apparently left his apartment without his wallet, cellphone or keys. The State College Police Department (SCPD) told the AP one of Steindorf's former classmates saw him Monday and brought him back home.

Friends of Steindorf were spreading news of his disappearance on social media Monday. SCPD Lt. Keith Robb did not give any details of the student's disappearance, other than there was seemingly no foul play involved, telling the AP Steindorf "just needed a timeout."

Joanne Steindorf, Jon's mother, told Reuters she spoke to her son Thursday and had no indication anything was off. She also said her son does not have mental illness in his medical track record.

"He was a very good student," she said. "He was in the [Penn State] Blue Band. He had a lot of friends. No one has any idea what has happened."

Steindorf told his parents he completed his business degree in the fall and elected to wait until the spring to walk in a graduation ceremony.

"We thought he'd graduate, and that was our understanding that he completed fall classes and he delayed graduation until now, but the most recent information we received was he was not on the list to graduate," Paul Steindorf, Jon's father, told the Centre Daily Times. "Apparently he wasn't enrolled this fall."