Every once in a while I run into that kind of reek in a grocery store. As you say, not the “I just mowed the yard/worked out and ran into the store without showering” smell but the “I haven’t bathed or laundered my clothes in weeks” version. The first smell I can deal with and won’t even notice unless I’m adjacent to that person. The other spreads a stench that lingers even if you’re in the next aisle. I had to pull up my collar to cover my nose and rush past to avoid retching the last time I encountered this. Is it a mental issue, or what? There are free showering and laundry options even for the homeless in my area.