Here is the message from my DM:
It's been getting kind of ridiculous. This is the third time we've had a situation where something happens unexpectedly or someone makes a sudden move, you can't be surprised ever, and then you roll a higher initiative, so it's like "This guy didn't make his move yet, but you just had a HUNCH he was going to suddenly cast Misty Step" or "PC didn't do anything yet, but you can just sort of tell that they are going to suddenly kick this guy". This isn't Diviniation magic, and you're not a Jedi, there's no way that being more "Alert" would cause you to predict events before they happen.
Comments?
This is a common problem with I GO U GO initiative systems -- the idea that nothing happens until your turn comes up. You could try to pitch the idea that things are happening all the time in combat (and before) but initiative is when you resolve it for game purposes. So the guy casting misty step isn't standing there drooling until his count comes up, doing absolutely nothing, instead his hand is waving glowy lines in the air and he's mumbling incantations under his breath but you're quick enough to jump in and stab him before he finishes.
The DM's job is to frame the situation so that everyone knows what's going on when he asks for initiative. When initiative is rolled, there should be zero doubt that bad things are happening and who's doing them. If you (as DM) are asking for initiative and not providing the situation so that players that roll high can make good decisions, you're essentially playing in bad faith -- you're shading the game so that players that roll higher than you still cannot react to your plans until after you've started them. This is not good play. But it's pretty much where most DMs start, so it's understandable. One of the big skills to learn as a DM is that your side is supposed to lose much, much more often than not, and that your job isn't to win combats or have your story told, but the present situations that the players can then react to and let that be the story.
If it helps, use the gunfight example. You're sitting in the saloon when Bad Bart bursts through the door screaming about how he's going to kill you for what you done to his brother. This is a surprise, but you're Nick the Quick, fastest hands in the state, so even though you had no idea Bad Bart was in town, you kick back from the poker table and pull your iron and get off two shots before Bad Bart can even finish swinging his shotgun to cover you. You're just that quick, and have a reputation for it. So when Nasty Ned, Bad Bart's other brother, comes for you, he brings the Nasty Boys with him and makes sure they go through the door first, screaming about how they're gonna do for you for what you done to Ned's brother Bart. Ned, being canny, steps over they're smoking corpses and levels his shotgun at you while you're reloading.
If, instead, the DM wishes to have a setting moment where a bad guy does something or says something and then gets away, either make the bad guy tough enough to survive whatever the party throws for a round before they escape, or else just narrate it -- the bad guy smiles and disappears before you can react. If you ask for initiative, you've got to deal with the fact that you might lose it. If this affects your game plans, then either deal with it or don't ask for initiative.