[cannam]

Heathrow Express has long been a bit lost. The original idea was that you would check in for your flight - including baggage drop - at Paddington before taking the Express. When the "lawn" area at Paddington was opened in 1999, the back wall (now a row of shops, from Boots to Fat Face) was a row of check-in desks with baggage facilities.

I never used these and I kind of wish I had, because after 9/11 they closed and never reopened.

[edit: Wikipedia tells me the check-in service ran until 2003 and "was withdrawn due to low usage and high cost of operation", nothing to do with 9/11. My mind must have filled in the more dramatic memory]

Then a few years later the Heathrow Connect service opened, a slightly slower, much cheaper alternative to the Express (it changed names a few times but I believe is the same service as now constitutes the Elizabeth Line on that stretch) - so nobody who was coming from Paddington, planning ahead, and paying their own fare had much reason to take the Express any more.