Chris Brown can sympathize with Conor McGregor -- telling us when it comes to his crazy bus attack, "We all get crazy sometimes."
Brown would know ... especially when it comes to smashing glass -- the singer famously hulked out and threw a chair through a window at "Good Morning America" back in 2011.
Chris was on probation at the time of the window-smashing incident stemming from another violent outburst -- the 2009 domestic violence incident with Rihanna.