The bus I've just come home on was full apart from one seat. But the person seated by the window had her legs swivelled round so that there was very little room left on the seat beside her. I carefully lowered one half of one bum cheek onto the remaining space and gave her a quizzical stare. She was a white- haired elderly woman of haughty demeanour who did not budge an inch but said defiantly, "I can't turn round because I've got a rucksack on my back". As I was tamping down the urge to enquire why she couldn't take it off and put it on her lap, she went on, "I've got to keep it on because it's full of heavy things". Curiosity got the better of me so I asked, "What sort of heavy things?" and the snappy rejoinder from her was , "Mostly nails". So I had to perch uncomfortably on quarter of a seat for the next 20 minutes while the bus crawled through heavy traffic from Clapham Junction to Wandsworth because this woman had a s***ing rucksack full of nails. I am still wondering what she needed them for. And rucksacks on backs on public transport are an abomination. Buses weren't designed to accommodate them. Specially when they are full of nails!