These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Mary Poppins
Canon Sue: It wouldn't be surprising if Mary Poppins's middle name was Sue.
She even gets a song about it in the stage musical. She's Practically Perfect, after all.
Base Breaker: Mary Poppins' strict and pompous behavior has won over some readers, who feel thankful that her personality doesn't taste like diabetes, and turned away others, who find her unreasonably heartless.
Sequelitis: The books seem to get less creative as the series progresses, at least to some readers.
There are also who think Mary Poppins is an irresponsible, dangerous drunk. She supernaturally "blows" the competition away for the job, then takes her charges to play with a homeless man. After giving them cough medicine. That tastes like rum to her.
Some people think she gives off a cold and dismissive feeling and would not actually be very successful with real children, like she was in the movie, in real life.
Given how dismissive she is of everyone she meets, except when they fall about praising her, Mary Poppins is some kind of high-functioning sociopath.
And yet, Pamela Travers (the author of the books), thought the Mary Poppins of the film, was too nice. Fans of the books often agree with her.
On the opposite end, people are split if Burt is totally mundane if charming, or if he's of the same breed of magical that Mary is (albeit in a much lesser capacity). The musical seems to support the latter.
Chim chiminey chim chiminey chim chim cheree, a sweep is as lucky as lucky can be! Chim chiminey chim chiminey chim chim cheroo...
Just...A... Spoonful of sugar helps the medicine go down, the medicine go dow-own, the medicine go down! Just a spoon full of sugar makes the medicine go down, in the most de liiiiiiiight-fullllll waaaaaaaay!
Feed the birds, tuppence a bag. Tuppence, tuppence, tuppence a bag! Feed the birds, that's what she cries, while overhead her birds fill the skies!
Famously, this song was a favorite of Walt Disney. Whenever he visited the Sherman brothers, he would say "play it". They would already know he meant "Feed the Birds" and play it for him. Even at his funeral.
Let's! Go! Fly a kite! Up! To! The highest height! Let's! Go! Fly a kite, and send! It! Soaring!
Supercalifragilisticexpialidocious. Even though the sound of it is something quite atrocious. If you say it loud enough, you'll always sound precocious....
I love to laugh! Loud and long and clear! I love to laugh! It's getting worse every year...
Step in time! Step in time! Step in time! Step in time! Never need a reason, never need a rhyme! Step in time! You step in time!
Hilarious in Hindsight: Julie Andrews and Dick Van Dyke disagreed on the radio talk show Hollywood Spotlight Microphone over the possibility of Mary Poppins getting a Broadway adaptation. Van Dyke strongly supported the possibility.
Memetic Badass: Mr. Dawes Sr. became this among italian Youtube Poopers, it all started with this (title roughly translates in 'Old Man Dawes will kick your ass!').
Purity Sue: A rare positive example, helped by Andrews's Academy Award winning performance, making Mary come across as a three dimensional character.
Dick van Dyke's accent was the result of his trying, and failing, repeatedly, to do a good Cockney accent. When it turned out he could only do a bad Cockney accent, he decided to make it hilariously bad.
They Just Didn't Care: The Masterpiece and Gold Classic DVDs trim the top and bottom of the picture. The 40th and 45th Anniversary DVDs show the full height, but snip a little bit from the left and right sides.
Wangst: Really, Uncle Albert, feeling upset about your guests having to leave soon is one thing, but have a crying fit about it is another thing altogether.
What Do You Mean, It's Not Didactic?: Some critics and academics have argued that the film encapsulates the societal shift of its time, with Mr. Banks representing the passing of the stuffy 1950s and Mary Poppins representing the arrival of the carefree 1960s.
In the musical, the contrast between generations is represented in the story, with George Banks, Miss Andrew, and most of the adults representing the older up-tight Victorian era while Mary, Bert, Mrs. Corry, Northbrook and a few others represent the much looser Edwardian era.