’Mad’ here means eccentric and these people were all a little peculiar as far as their habits and behavior is concerned.
1. Hetty Green
Hetty Green was a miser because of which she collected money and was considered to be the wealthiest at the time. She worked at a bank but because she did not want to pay rent, she did so out of a trunk. She wore the same outfit and the same underwear till she was sure it was no longer wearable.
2. William Archibald Spooner
Spoonerism is that linguistic method which involves the intentional or accidental exchange of vowels, words or letters in a sentence. William Archibald Spooner invented this phenomenon as he would often speak in such a way that the letters were all mixed up and the sentences rarely made any sense.
3. Simeon Ellerton
Simeon Ellerton was an eccentric man who was fanatic about staying fit. He took up the position of the local courier during the 18th century as it would allow him to walk for several miles at a time. During these walks, he would collect stones and carry them back on his head as he wanted to make a house of stones. Once that was done, he felt quite odd when he walked without the additional weight on his head so he started carrying bags of stones again for no particular reason as such.
4. John Christie
John Christie started a well-known Opera festival in England. He did not like tipping anybody so he carried his own bags when he traveled but spent massive amounts of money on Opera productions. If the weather was too balmy, he would cut the sleeves of his jackets.
5. Oscar Wilde
When this famous poet was enrolled at Oxford University, he used to tie a leash around the lobster and walk it all around town.