The Monkees originally referred to Mike Nesmith's character simply as ''Wool Hat''
He actually wore the wool cap to his Monkees audition.
Everybody knows the Monkees, right? There's Davy, Micky, Peter and, you know, Wool Hat.
That's what The Monkees producers first dubbed Mike Nesmith and actually did use the nickname on air, intending to call the character that throughout the series run. You can even see it listed in the earliest Monkees promo materials, like this old TV Guide listing from 1966:
It also might surprise you to learn that the story behind Nesmith's green wool hat that he wore in many of The Monkees episodes is one of necessity. Despite being in sunny California, Nesmith had donned the wool cap to keep the hair out of his face while riding his motorcycle to his Monkees audition. He had no idea it would become such an integral part of his person from that point on.
In case you didn't realize, Nesmith's screen test ended up being so hilarious that when The Monkees pilot first didn't perform very well with audiences, the producers re-cut the episode and stuck Nesmith's and Jones' screen test in front of it. Once they re-aired it, suddenly everybody loved The Monkees. Call it the power of the wool hat, but producers latched onto the cap as Nesmith's calling card early on and tried to force the fan connection to be just as strong as theirs, by making it the character's name on the sitcom.
In the end, the reason we don't call Mike Nesmith Wool Hat is pretty straightforward, too. Nesmith didn't like being called Wool Hat (it's about the plainest name we've heard since Tom & Jerry called its star Tom Cat), so the producers dropped it, letting him be known by his real name Mike, not the hat he happened to wear on the first day he walked on set.
Wondering what happened to that famous wool hat? Nesmith hatched a pretty clever scheme to be rid of it for good. At a concert, the story goes that he tossed it out to a fan in the crowd. (Talk about the ultimate Monkeemania memorabilia!) The only way his plan would've been more perfect was if maybe he timed it out and tossed the hat away during a performance of the Monkees song "I Wanna Be Free."