When I first arrived in England, one thing that really hit me (besides the fact that I had barely slept on the plane - thanks endless movie selection!), was how small everything was! For starters, I could barely get my luggage through the turnstiles, but it went through airport turnstiles just fine at home. This could have been in part due to my sleep deprivation and hence my probably somewhat compromised motor skills, but in my defense, my dad, who had slept just fine on the plane, was unable to get through the turnstiles as well!
After some heavy lifting, I managed to get through, but I soon encountered another size challenge: the Tube, a cool name for what we call the subway. When I stepped into one of the cars, I found myself unable to stand up straight without hitting my head against a pole. A little uncomfortable, but at least it kept me awake for the duration of the ride from Heathrow airport to central London! Such a situation would have been unthinkable though for me back in the States, where there always has been ample head room in the subway. It turns out that the design of the train I was riding was due to the shape of the tunnels, which pre-dated the Tube. I wonder though if it would have been possible to reshape the tunnels to accommodate for taller trains. Perhaps someone can enlighten me?
I could go on about describing numerous other situations of "smallness" that I have encountered, like eating at a restaurant where an 8-oz. steak cost 22 pounds (33 dollars!), Whole Foods paper bags that could barely fit a bottle of milk, narrow dorm hallways (picture below; note that the ruler is there to provide an idea of the width of the hallway) that barely allow two people to be in it at once, or the narrow walkways and sidewalks that made it challenging at times to get around people without having to venture out onto the street and risk getting by a car or a bicyclist coming in the opposite direction that I would expect. However, that is besides the point.
Yes, England may be smaller (except for its buses perhaps), but that doesn't necessarily mean that it is worse. People, even larger people such as myself, have managed to make those narrow turnstiles, low Tube ceilings, and small Whole Foods bags work. In fact, the smallness can be beneficial because it forces you, as it has for me, to be more aware and conscientious of what you do. For example, a narrow walkway means that you have to devote more of your brainpower to actually walking instead of say texting or messaging unless you want to run into someone else or wonder onto the street and get hit. Small Whole Foods bags might make you think more about the groceries that you purchase given the space constraints and perhaps consider using your own reusable bags for shopping, especially if you still like buying groceries all at once or in bulk, since the store won't provide such large bags for you.
The smallness may be a bit of a shock at first, though I hope it will be less so now that you have read this post and have been forewarned! :) Nevertheless, as you start to adjust, you will hopefully start to see and appreciate the benefits it can offer.