But the CO2 levels are getting bad anyway, and we don't want to make things worse. After all, the same people who have problems with masks also are completely on top of the science and actively support...
*whisper whisper* ...what was that?
*whisper whisler whisper* Oh. Right. Never mind, then.
...
When walking out and about and crossing paths with others at the side of the road, if I can't easily step off into the road as (self-serving?) courtesy because of a vehicle - and odds are that I am alone and they are multiple, so it is always the lesser fuss that I do this - then I find myself holding my breath as I give the habitual smile and nod that passes for the absolute minimum greeting I'm prepared to give such a random encounter.
I do this consciously but not deliberately, and I thought about it enough already to benchmark it. It starts about 10 quick paces from the crossing (so ~20 paces or so of initial separation as we converge), and if sufficient reason arises to advance past smile[1] and nod, and furthermore also some gesture of the hand (though that'd be more for cross-street greetings).
I am left untroubled in releasing my held breath to utter a few words, nor does it trouble my conscience to go against my prior precautions. Though if I do speak, I then do not continue and re-inhale until beyond the encounter, and if I do not I cycle my whole lungs only at that point.
In doing so, I'm doubtless subjecting myself to a degree of anoxia
far greater than anything any cloth or other particulate-filtering mask does, for the same amount of time. I have reason to believe I've got good lungs on me, though maybe not as good as in my prime, so perhaps I'm just more resilient to transitory events[2]. Or maybe someone is confusing masks with plastic bags.
[1] Not wearing a mask at all in the open air, as I think I explained before.
[2] As I type this, no effort like walking involved, or even standing up, just tap, tap tapping away, I can use the clock in the corner of the screen and easily hold a deep breath from one minute changing until well after the next one does. Longer if I start to let loose a measured exhale as it 'feels' bad, and beginning with a more sensible preparation than on the spur of the moment gives me beyond double the original time.