Back in high school I knew a guy who memorized pi out to 100 places. If I recall correctly its digit sequences never repeat themselves.
"The record for the most digits of pi memorized belongs to Rajveer Meena of Vellore, India, who recited 70,000 decimal places of pi on March 21, 2015, according to Guinness World Records. Previously, Chao Lu, of China, who recited pi from memory to 67,890 places in 2005, held the record, according to Guinness World Records."
From:
10 Surprising Facts About Pi | Live Science