Or President X, or General Y, or Mr Secretary, even for people who no longer hold those positions.

And for the record, Sir is an ancient military title just like Captain.

Absolutely!

Another example is HIV: Initial infection is just a minor flu, you’re then infectious and active for 5-10 years before becoming seriously ill with AIDS (of course this is for untreated HIV). This allowed the illness to spread for decades adapting to humans before finally being identified in the 80s, killing millions.