Observations after three days in London:

The city is FAR more casual than it was last time I visited. A few decades ago the sight of tennis shoes screamed AMERICAN!

No more.

Everyone is wearing tennies. (Except me, I didn’t bring mine.) And jeans. (Again, I left mine home.)

Looks like our strongest allies are also picking up other American habits. We eat constantly and on the run. Guess what? So do Brits. Ice cream, chips, candy, hotdogs, pizza, they’re eating while walking. And American food chains proliferate: Five Guys, Chipotle, Wing Stop, Fridays and Starbucks to name a few.

Let’s just say we aren’t sending our best gastronomic experiences overseas.

Get this: Londoners are even eating INSIDE the West End theaters. We went to a production of “Wicked” tonight (it was spellbinding) and I was shocked to see people carrying tubs of popcorn, ice cream, beer and even bottles of wine to their seats as if they were at a sporting event.

It’s been a while since I’ve been to Broadway. Are people eating and drinking inside the New York theaters, too?

Refreshments should be an intermission thing, consumed in the lobby. Who can’t survive 90 minutes without grazing?

The real downside: The theater floor looked like a Superfund site when we left. This was in the lovely art deco Apollo Victoria Theatre that’s almost 100 years old. Seemed a sad way to treat the old girl.

Two other things I noticed that are probably related: Brits don’t seem as obsessed with hydration as we are. Haven’t seen a Stanley since we arrived and people are not strolling around with water bottles. There are also few public bathrooms. Coincidence? I think not.

Today’s highlights were our tour guides. I don’t know if we lucked out or if this is a talent shared by all of those in Britain who squire strangers around their fair city.

First up was Richard Delroy. Remember his name. He’s an actor without a gig right now, but if he someday strolls up to accept an Oscar we can say he once led us on foot around the city in search of all things Harry Potter.

Our little J.K. Rowling fan was eager to take a three-hour Harry Potter walking tour of London. So we met our energetic guide at the 9 3/4 sign in King’s Cross station Tuesday morning.

On this chilly, raw morning there were just seven on the tour: us and a Croatian family.

I may be the only person to wander miles of London looking for Harry who’s never read a single Harry Potter book nor seen any of the movies. My kids read the series with my husband and he was the one who drove them to Borders Books at midnight to get the first releases of new books. It was a daddy and kids thing, I let them have it and didn’t intrude.

Nevertheless, the tour was fun and informative and Richard’s patter made the three hours fly by as we walked through Chinatown,Trafalgar Square, the West End, past Whitehall, the Houses of Parliament and down endless narrow mews searching for Potter trivia, like doors and windows that were featured in the movies.

By the way, Richard told us that the reason the author invented a 9 3/4 platform at King’s Cross was as an ode to her parents who met and fell in love between the 9 and 10 platforms.

Sweet story.

That tour ended near the Tower of London, which is on everyone’s list of things-you-must-see-in-London. As we entered the ancient grounds the ticket taker told us a tour was just starting.

We jumped in.

What luck!

Our guide was one of the Yoemen Warders - known as Beefeaters - a Scotsman named Tam who has an encyclopedic knowledge of English history. His stories of the executions were delightfully vivid and I watched as my granddaughter eagerly wove her way to the front of the crowd to hang on every word about the botched beheadings and other bloody doings that happened right where we were standing.

Tam didn’t hold back and the crowd loved it.

It was cold and gray - typical weather for this time of year - but Tam’s energetic presentation made it all bearable. We were reminded again of England’s long and rich history. The Tower was built by William the Conqueror in 1066 and its walls are 15 feet thick. It was a fortress, a prison, a palace and London’s first zoo.

Beefeaters guard the Tower and the Crown Jewels that are kept there, they’re also the king’s bodyguards.They each have at least 22 years of stellar military service before being selected to put on the recognizable navy and red uniforms. (Tam served in the Air Force.)

Outside the building housing the Crown Jewels was an intricate maze of barriers, presumably for the summer when long lines snake through the tower.

The biggest advantage to traveling in early March: no crowds. Just us and French students.

Our treks around a strange city highlight one big difference between Boomers and Millennials. I have a paper map of London marked up with the places we want to see. My daughter whips out her phone to use Google maps and has no trouble walking with her GPS held aloft in one hand. I will admit that her directions are much better when trying to sort out the confusing tube and bus system.

Still, I like to remind her that if the satellites are ever attacked only people my age will be able to navigate, since the art of map reading is lost on the younger generation. They’ll wander in circles, staring at their blank screens while we boomers will unfurl our maps and be on our way.

Wednesday morning update: Super Tuesday results. No real surprises so far. Delighted to see a Steve Garvey matchup against the odious Adam Schiff in California. Perhaps Golden State voters will finally wake up and stop electing nuts.

Looks like Virginia’s proposed medically assisted suicide bill has been tabled for this session. Great news!

Oh, and look what happened in the Green Mountain State. Haley wins.

As Vermont goes, so goes the nation.

Said no one ever.

More tomorrow…