Pantene
When P&G started to mass market this stuff, back in the 80s, the advertising budget must have run into the tens of millions
There were ads in magazines, on billboards, on every ad break (two commercial channels back then) and all over public transport
The constant ads, where the woman with the long, shiny black hair being released to hang free to show us how healthy her hair was, grated on every nerve
So I have not bought Pantene
I will never buy Pantene
I won't try a free sample
I won't pick it up from the reduced section at a shop
If I'm somewhere else and the shampoo is Pantene, I will use shower gel or bubble bath instead of Pantene
I have used Radox instead of Pantene
All because of an ad campaign 40 years ago
Inconsequential and petty, I know, but the OP asked for irrational