My wife gets me every year with the same gag (or a variant thereof). I can't hear the phone ringing sometimes, so she brings me the phone and says it important, it's your boss, or something, and there is no-one there.....
I fall for it every time ' cause I never remember what the date is.
I usually don't mind April Fools jokes if they are clever. I mostly don't fall for the clever ones, just the dumb ones. Shows what kind of person I am I suppose.