Years ago, before I got into IT, I was a trainee accountant.
I worked at this somewhat snooty Chartered Accountants office on Cook St, near the Coventry Theatre.
I was the junior guy and the four or five other guys, who had all been there for years, thought I was wet behind the ears.
One day, soon after I started, they decided to have this competition where we would all add up this long list of huge numbers.
The one who got the total right in the quickest time would be the winner.
I'm sure none of them gave me any hope, but I beat them all easily.
After that, I think I gained a little begrudging respect from them.
Another time in a completely different job in IT, I worked in a room with two other guys. One of them was looking for a solution to a really tough problem and he ended up with an equation, the answer to which would be the solution.
I forget the term for it, but it was where you have one expression equalling another expression and you have to reduce one side to a single variable.
He'd been trying to solve it for ages and failed to get a solution from any of the people he thought could help
No-one was aware I had any maths ability, but I offered to try and solve it.
It took me about about half-an hour and a dozen or so steps to reduce the equation.
There have been a few other examples of where I was underestimated and ended up surprising people, but the above two stick out in my mind the most.