Old football injuries, side effects of Lyme disease and age have taken a toll on Kris Kristofferson's memory. But they haven't changed his gruff attitude one bit - especially when it comes to smoking marijuana.

"Do you think the weed hurts your memory?" Rolling Stone's Neil Strauss asked the legendary country singer/songwriter in an article published earlier this month.

"If it does, it's too bad. I'm not quitting," replied Kristofferson, who turns 80 today. "I'm sure that it slows me down and doesn't make me the sharpest-witted person in the room, but I'll probably be smoking till they throw dirt on me."

For fans, his reaction is a comforting reminder that the man remains the same even if he can't - as Rolling Stone discovered - remember his legendary recordings or the tunes that he wrote for other musicians, including Janis Joplin's "Me and Bobby McGee" (1970) and Sammi Smith's "Help Me Make It through the Night" (1971).

But like his belated friend and fellow Highwayman Merle Haggard, Kristofferson doesn't intend to let his health get in the way of performing. Kristofferson is touring this summer with Willie Nelson, as well as The Strangers, Haggard's former backing band. Based on his vow to keep toking, your nose will tell you when Kristofferson and Nelson roll into town before your ears catch word of it.

Smoking up is part of Kristofferson's legacy as a country music icon. Marijuana helped him and Nelson define themselves as part of the "outlaw country" subgenre that rejected the polish and flair of contemporary performers in the 1970s. And Kristofferson not only enjoyed puffing a joint but also wrote about in songs like "Sunday Morning Coming Down" - which became a hit for Johnny Cash in 1970.

When "The Man in Black" performed the song on television that year, he was asked to change Kristofferson's controversial lyric, "I'm wishing, Lord, that I was stoned." But in true Highwayman fashion, he refused.

Check out Cash defying the censors in the clip below.

banner image: Flickr/Bryan Ledgard