My theory on major software developers skipping version numbers beginning with 4

My theory, and only a theory, on why major software developers skip software version numbers beginning with the number 4.
If you go around looking, you’ll notice that many software vendors skip the 4. In a few oriental languages, the number 4 is an unlucky number. Forexample in Chinese, it means death.
What more can I say about this, other than it’s a theory only. Notice that Dos 4 was skipped, Windows 4.0 [Argueably NT could be it] was named Windows 95. Winamp…
There are many other things out there too… if you know of any other versions that skip the number four, please share it.