In Johnson's 2000 autobiography "The Rock Says" (Page 147), available via the Internet Archive, he said the Stampeders' training camp began in June 1995, further confirming he was 23 at the time. (The May 31, 1995, date of the Calgary Herald article suggests the training camp may in fact have started slightly earlier.)

Finally, The Rock is explaining why he wasn’t at WrestleMania. On Tuesday morning, Dwayne “The Rock” Johnson appeared on “The Pat McAfee Show” to explain his absence

After not being booked for WrestleMania 41, Dwayne "The Rock" Johnson was shocked to see Travis Scott help John Cena versus Cody Rhodes.