Kelly Brown knows better than most that stammerers come in all shapes and sizes. He also knows the sight of a brute of a man struggling to get his words out at a public function can make some people feel particularly uneasy.
"There's always a dinner after a Six Nations game, with speeches from the two captains," says the Scotland skipper.
"I like to start off with a stammer joke because it puts everyone else at ease. Like this one: 'My dad was a very generous man. He gave me three things - my stammer, my ridiculous eyebrows and a girl's name. Thanks, Dad.'
"The only problem is I've now been captain 12 times and it's becoming increasingly difficult to think up ways of taking the mickey out of myself. So if anyone out there has got any suggestions, I'd love to hear them."
The Saracens flanker, 31, has not always had such an easy relationship with his stammer, which first manifested itself when he was all set to make a speech in school assembly.
"I couldn't say a word," says Brown, whose side lost 28-6 to Ireland in their Six Nations opener on Sunday.
"The silence felt like hours. A couple of kids started to chat, wondering what was going on. I've never been shy but it wasn't a nice experience and it did affect me. When you're in that situation again, you fear it."
But Brown, neither broken nor bitter, continued to thrive, on and off the field.
"Kelly is a role model in many ways," says Alastair Kidd, Brown's old rugby coach at Earlston High School in the Scottish Borders. "The way he's overcome a social impediment through hard work and application is something to be admired."
Brown represented Scotland at four age levels and studied sports science at Edinburgh University before turning pro with the now defunct Border Reivers.
In 2005 he made his senior Scotland debut, in a non-cap international against the Barbarians. But having established himself in the side, Brown began to wonder whether his stammer would prevent him from making the next logical step.
"I was picked to start the first game of the Six Nations in 2010, against France," says Brown. "I did an interview and I felt it was so bad that I phoned the Scottish media manager and asked if he could make sure it was never shown.
"I was so embarrassed by it. I would stammer, blink, rub my eyes. That was the point when I said, 'right, I need to do something about this'. I was sick of wondering 'what if?'
"I felt I could be a captain but if I was a coach, I wouldn't have made me captain. I wanted to give it my best shot and that's what I did."
Brown enrolled on the McGuire Programme, which teaches cyclic breathing exercises and helps combat the psychological aspects of stammering.
"It's about self-acceptance and never letting the fear hold you back," says Brown.
"I've got to work on my speech every day but if I work hard it's not a problem. I say to the guys: 'Listen, there may be days when I'm having a bad time or I've not been working on my speech as normal.' So it's never an issue."
One man who is fulsome in his praise for what Brown has achieved is Scotland head coach Scott Johnson. The Australian was Andy Robinson's assistant the day Brown first captained his country, when he won the 50th of his 61 caps, against the All Blacks in 2012.
"What inspires me is people who overcome adversity," says Johnson. "It's not a massive adversity compared to others, granted. But to do what Kelly has, stand up in front of people every day and speak, this kid's an inspiration."
Johnson may be right, in that some would argue there are far greater impediments in life than the possession of a stammer. But Brown's ability to overcome his impediment - indeed, tweak its nose, stuff it up his jumper and run with it - will embolden others who currently feel their ambitions are beyond them.
"In last year's Six Nations, we were playing France in the final game," says Brown. "Thierry Dusautoir tossed the coin and I wanted to call heads.
"At the last second, just as the coin bounced, I blurted out 'HEADS! HEADS! HEADS! HEADS!' Nigel Owens, the referee, turned to me and said: 'You only just managed to get that one out there in time.' We had a laugh about it.
"I never thought I could be Scotland captain, so to get to do that now makes it even more special. I always will have a stammer, it's all about accepting it. It's just part of who I am. My message is simple: if you've got a dream, go for it."