There are a a lot of things in life that it is impressive if you can list them from memory: the actors from the Magnificent Seven (I can't, I just had to play 20 questions with the Better-Half to remember the name of the movie!).
Then the Kings and Queens of England "Willie, Willie, Harry, Stee, Harry, Dick, John, Harry Three, Ned the twain then Richard Two, Henry Four, Five, Six then who? Edwards Four, Five, Dick the bad, two Henries and then Ned the lad. Mary, Bessies, James the vain, two Charlies and then James again.William and Mary, Anne Gloria, four Georges and Victoria. Edward Seven next and then George the Fifth in 1910, Ned the Eight soon abdicated and George the Sixth was coronated; and now we have Elizabeth and that's all folks (until her death).
The States of America is a feat (I like most people seem to manage about 46) and even better if you can follow that with the state capitals (matched to their states). Or for the faint hearted, how about the Great Lakes?
My favourite to list though are things connected with London. There are 32 Boroughs that cover London, there are 25 wards in the City of London, and there are 14 road bridges crossing the Thames in central London, which I toughed on in the post about the Thames.
The bridges in the East for me are easy, I live in South East London and I cross a good few of them regularly. The further West we move the more confused I get. Naming the bridges is interesting not just because it is a show-off thing to do, but also because all the bridges have fascinating histories. We'll meet a few of them over the week.