Outside is Bigger Than Inside

This is true almost all of the time. Let’s leave the Tardis out of this.
It’s particularly evident when the inside is a fairly confined space like a streetcar, bus or elevator. Outside is bigger than inside and the doorway is smaller than either. Let people make their way outside (which is bigger) before you try to shove your way inside (which is smaller) through the doorway (which is even smaller). 
Thank you.