That would be me then because we were taught metric at school. I found it confusing growing up with two sets of measures. Also growing up just after the currency denominations changed. So my parents would keep calling 5ps shillings. Metric is useful for measuring things in cm and mm, but use miles & pints rather than KM and Ml. Useful for scientists but not the average person in the street.
I remember when I had to hold one in both hands when I was younger. I was in my teens before I could actually finish one entirely. I wouldn’t know one if I saw one now…
A4 and Fullscape are two different things. Fullscape was always a bit longer I think. Haven’t seen it used for years now.
See here:
Letter at 279mm (11.0") is slightly smaller than A4 at 297mm (11.7"), both Legal at 356mm (14.0") and Foolscap at 330mm (13.0") are longer than A4 with Legal being the longest. Foolscap is the narrowest at 203mm (8.0"), followed by A4 at 210mm (8.3") and then Letter and Legal at 216mm (8.5").