Billy Crystal - who turns 68 today - is undeniably a comedy legend. But when he was just another up-and-comer, his first big break was actually a bust, all because of network practices regarding marijuana.

Back in the early 70s, the "When Harry Met Sally" star was a member of the struggling comedy trio "3's Company". However, opportunity came knocking when they were signed by TV host David Frost to make an appearance on a network special called "That Was The Year That Was" (1973).

The comedy troupe performed their best bit - a cannabis commercial. In his autobiography "Still Foolin' 'Em" (2013), Crystal wrote,

"Our sketch documented the making of the first marijuana commercial. (It was our best piece.) I played a stiff...actor who gets progressively smashed as he does take after take, smoking 'the product.' We taped the show, and the audience loved it."

However, the broadcasters weren't as amused:

"What we didn't know was that the network wouldn't air the sketch because it was about pot. Our agent couldn't reach us, so there we were, first all excited, then freaked out as the show went on and on and no "3's Company". Finally...the credits rolled, and there we were, smiling and waving, standing next to the hosts. They were able to cut us out of everything but the closing credits."

But he still got kudos on the performance. Once the credits finished, Crystal wrote, "The phone started to ring. It was the relatives: 'Very good waving,' 'You looked good, Billy, I like the way you wave.'"

Unfortunately, the controversial commercial appears to be lost forever. But you can watch Crystal reminiscing about smoking a joint with his grandfather in 1967: