> I am reasonably certain I had covid in January 2020 Probably not, there were nasty flu strains circulating then that are much more likely an explanation. It

> I am reasonably certain I had covid in January 2020 Probably not, there were nasty flu strains circulating then that are much more likely an explanation. It had already spread somewhat, but not enough to be a likely cause until March even in the areas with early outbreaks like Italy and NYC etc. Exponential growth means that not long before everyone has it, the vast majority don’t have it.