'I’ve finally been getting to grips with solid bars, powder-to-foams and cremes,' says Jan Masters - getty

‘Take two bottles into the shower?’ That was the question posed by the woman in a ’90s shampoo ad set in a gym changing room (POV: back of locker). She slammed the notion of using a separate shampoo and conditioner because both coexisted in Vidal Sassoon’s Wash & Go. Back then, though, the sell wasn’t about reducing plastic – you were simply an idiot if you didn’t want nicer hair, faster. A knock-on effect was that you could no longer use the excuse ‘I’m washing my hair’ to get out of a date, which in days of yore had been deemed acceptable. ‘Ah yes, a lengthy process. Maybe another time.’