Many tenants have ditched their masks or are only covering their mouths or (even worse) their necks. If you breathe through your nose, please cover it as well as your mouth. (Surgeons are often masked for many hours and don't suffer from a lack of oxygen.)
You don't know whether the other person on the elevator with you or in the corridor has been getting chemotherapy, or has a child who's immunocompromised, or lives with an elderly parent with breathing difficulties. And we don't know whether we currently have COVID without symptoms - and can spread it even if we're vaccinated. (Yesterday's test is already outdated.)
So PLEASE wear your mask every time you step out of your apartment into the corridors and laundry rooms - and please get vaccinated. Almost all of the hospitalized people with COVID are there because they were not vaccinated.