When I was in my teens I went into a chemist with my sister to buy some lillets. There was a road being drilled with a pneumatic drill just outside so it was very noisy, I had to shout very loudly 'a packet of Lillets please' The chemist reached behind and put a packet of Gillette razor blades on the counter so from then on we always called them razor blades.
Waiting for memory clinic referral

