After a year and a half of the pandemic I still sometimes leave my condo forgetting to put on a mask. Usually I realise within a few seconds and go back. A few days ago I got halfway to Foodmart and then the long hard glare I got from a farang told me something was wrong. I popped into the 7/11 I was passing, hand over mouth, and apologetically explained the situation. The girl assistant produced a pack of three (not that kind of pack) for I think 12 baht and I was back in business. Gaybutton is right: you won't get far in Thailand currently without a mask.