Well, we know that he lived in London in the year 1910, and worked as a Chimney sweep, Screever (chalk artist), and part-time kite salesman.
We know he had a friend named "Mary Poppins" who was a nanny. Along with Bert, and the two children in her care, Jane and Michael Banks, they had a very well-documented adventure.
But after Mary Poppins floated away on her magical umbrella, what ever happened to Bert?
Well, Ben and Joe have helped me figure it out.
Apparently he moved to the English countryside.
We lost track of him for quite a while, but it
does seem like at some point he got married and had two children of his own, Jemima and Jeremy. Unfortunately, he also became a widower at some point.
Things began to turn around when he decided to invent a flying car named "Chitty Chitty Bang Bang" and fell in love with wealthy candy heiress "Truly Scrumptious."
The only part we can't figure out is why he started going by the name "Caractacus" after he left London. Our best guess is that his full name is "Caractacus Bert Potts."
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I'm 99% sure that this is what Ben & Joe actually think. Dick Van Dyke is always referred to as "Bert" regardless of which movie we're watching.