The only thing worse than having to deal with AoO is having to deal with all the situations that provoke AoO without them.
I speak from experience, as a DM that was well on the way to independently developing the AoO in 1st edition. The game is much simplier to arbitrate if you have AoO than if you don't, because you have clear guidelines for what players can safely do and you have much less arguing over the rules and fewer fiat rulings you are forced to hand down. This lets you concentrate on game play.
And to be perfectly frank, if you can't memorize the AoO rules well enough to serve, then you don't need to be DMing. They aren't that bloody complicated.
If you must simplify them down consider the rules to be the following:
"Swift actions never provoke an AoO. Otherwise, if you are in a threatened area and you do anything at all that doesn't directly involve protecting yourself, you provoke an AoO."