I'm sceptical about most things but the nail in the coffin of "unlucky" numbers must surely be that they are different in different cultures.
In the US you mostly don't see floor 13 in buildings, here in Malaysia 13 is there but not only is 4 missing but other floors with 4 such as 14 are replaced by 13A!
The building I'm in has two towers that are linked but are at slightly different heights. Most of the floors continue through but one tower has a floor zero.
Had some trouble with my access card and as part of my tests I tried the other tower elevator. The head of security noticed this in the log and explained that the card only lets me use the lift in the tower I'm in for "security", but when I pointed out that you can just walk between the towers he remained convinced it was a good feature.