“Weaken the immune system” not like with muscles from lack of physical exertion, but like with an antivirus database that stops receiving signatures from the ongoing evolution of viruses around.
My mental model (would not mind if it is wrong) suggests that the number of distinct viruses in our environments is surprisingly high (I do not think we have identified all of them yet), and it is thanks to continued repeat exposure (re-training immune system to mutations, etc.) throughout our daily life that we do not get constantly sick.
Not to say I think it would be disastrous for a person to stop wearing a mask after a while of wearing mask properly—one would just be ill for a bit, like you say. Although I would presume combining multiple infections at the same time could make it a little less pleasant.
My mental model (would not mind if it is wrong) suggests that the number of distinct viruses in our environments is surprisingly high (I do not think we have identified all of them yet), and it is thanks to continued repeat exposure (re-training immune system to mutations, etc.) throughout our daily life that we do not get constantly sick.
Not to say I think it would be disastrous for a person to stop wearing a mask after a while of wearing mask properly—one would just be ill for a bit, like you say. Although I would presume combining multiple infections at the same time could make it a little less pleasant.