I saw all the movies when I was a kid and I just finished book 4 last night and I'm still not getting it. Is there a practical reason everyone is afraid of saying the name "Voldemort" while instead referring to him as You-Know-Who and He-Who-Must-Not-Be-Named?
And I'd prefer an answer better than "...because he's so eeeeeevil!"
Dumbledore, Lupin, Fudge, Mad-Eye, Harry, and others all say his name liberally without any adverse effects. Even those that are reluctant to say his name at first like Hagrid and Minerva eventually mutter his name and get on with their day.