Hahaha... I had the same realization two weeks ago, at Walmart, in a suit and tie, reading the water labels and then checking out with 10 gallons of water and nothing else. Normal people don't do that
I bought 10 gallons of distilled water there a few weeks ago. Got some strange looks. That's hard to do at Walmart - considering all the other 'interesting' people there.
I told the cashier at a local grocery store (after she asked) that the reason I was buying 10 gallons of RO water was to make beer with.
Immediately she went pale and got real cagey, as if I had just told her I was buying their entire stock of Sudafed to cook methamphetamine to distribute to schoolchildren. Before that she had been real friendly and flirty.
There was a line behind me, so I didn't bother to explain the legalities of homebrewing. i'll just let her stew on it until next time....