Re: Dumb question
Try casting to a point a few feet above the water. Casting to the water tends to give you a "hard" landing, which, in a lot of cases, will spook the fish that you're going after.
The hard stop on the forward cast is important; as is a hard stop on the backcast (for the same reason), but try for an imaginary target just above the water and let the fly float down onto the surface.
Also, if your front line/leader is pudding on you (not straightening out at the end of your cast), then have a look at your casting stroke. I think you're likely to find that it's very fast at the start and much slower at the finish. For most purposes, this is just the opposite of what you want. It's a little un-natural for some to start the cast slow and to accelerate it up to the point of the stop, but it works very well and it's one of the best ways to be able to feel the rod load with the line. Once you can feel that loading, your casting will, I think, be a lot better for you.
The quick start / slow finish cast is also one of the prime causes of people "horsing" a rod; putting so much power into the cast that it, more or less, negates the inherent effects of a loaded fly rod.
One final thing to consider. Sometimes, in an effort to get the fly to just where you want it; just a little further out than on the previous false cast (assuming that you're using one or more false casts), people make the final forward cast a little more energetically than the previous false casts. This generally translates into a faster start and a slower finish and often times doesn't give them the effect that they're looking for. Try to resist the urge to make that final forward cast just right and keep the same rhythm and speed that you used on your previous false cast(s); let the rod do the work. Of course, if you're picking up from the water and casting out again, you wouldn't encounter this point as much.
Good luck with it!