Some of us - those with mobility problems, for instance - have no
choice but to use a packpack.

I use a crutch, and need my other arm free to hold on to moving buses,
Underground cars etc. But 2-3 times a week I also have to carry my 'gym
kit' for physio sessions in addition to day to day items. Here's
yesterday's load:

packed lunch, 2 apples, 50cl water

2 business files, notebook and A4 pad

laptop and compact camera

shorts, T-shirt and toiletries

... all of which were either essential or (deodorant, toothpaste)
highly desirable

If the train is standing at a platform, and space & time permits, I
hand-carry the bag on board, but that's not feasible if I need my spare
hand to grab a rail and "hold tight" as bus conductors of old would
call.

But reboarding [if that's the phrase] a Circle line train at Edgware
Road yesterday I was taken aback to see a woman accompanying what I
assume was a picture or print of some sort - a size I can only describe
as "bigger than A0 - more than half a door" It blocked off both her
seat and the next two down the car.

Several passengers asked her to move it, with varying degrees of
politeness. All to no avail - a shrug was her only response until
another 20-something woman told her brusquely "stand it up - or walk
home and let more intelligent people have a seat".
--
Writer / editor on London's River