Reformed rock wildman Ozzy Osbourne still faces interrogation by security officers at border crossings because of his drug-fuelled past.
The former Black Sabbath frontman famously spent 40 years of his career on drink and drugs, but now he's warning fans their teenage follies can come back to haunt them.
In his column for The Sunday Times Magazine, Osbourne writes, "The trouble is... doing a stupid thing will always have a stupid result... because I got caught smoking a reefer a long time ago, I still have problems getting into and out of some countries to this day.
"A lot of us do bad things when we're young, but those of us who learnt (sic) the hard way need to teach our kids to think of the consequences..."