But... I'm really not. I know very well the difference.
I guess I misunderstood what was being talked about, but I was actually trying to make the point that movement between Shengen and the UK is different from movement within Shengen.
Specifically, I was answering to this exchange:
>> it was always more difficult to go to/from the UK
> This is not true.
by saying that it is actually more difficult to go to/from the UK. Which it is.
Schengen agreement mandates no border check, but the UK is not part of it, so of course they can have border check