No.
First of all I will put this question to you. How far do you think a trout will follow a fly in still water?
Well I can assure you that they will quite often follow a fly a considerable distance before taking it, or not taking it at all. I have seen this happen many times. I have had trout follow my fly right into the margins on many occasions.
You know what happens then of course? They are spooked by your presence and often you get a swirl in the water, especially if it is shallow, just as you lift your fly out. You then say: "Hell, look at that fish, he missed taking my fly." In deep water you often see nothing.
He may have missed taking your fly, but what has most likely happened is the trout has seen you and scarpered, taking half the fish away with him to the other side of the lake.
So how do we avoid this quite common occurence?
Once the fly has passed the trout's prime taking zone, we get the fly out of the water as quickly as possible. If the water is clear and deep, you must do this before the fly gets within about 15 feet of you. Remember due to the angle of refraction, A fish can see you easier in deep water than in shallow.
The best way to remove your fly from the water is to roll cast it out. All you need to do then is a couple of false casts and out again 30 yards or so. Get the fly back to the taking zone as soon as possible and cut your false casting down to the minimum. 2 or maximum 3 false casts are all that are required to send your flies back to the taking zone.
After you have fished and caught a few fish in a certain spot, you will notice that there seems to be a definite taking zone. It might be 20 yards out, it might be 15 yards out, but you will spot this area and you can be almost dead sure at times that you will get a fish there.
Don't waste time retrieving your fly too close in, which just might make a trout come too close to you and be spooked. That fish will most likely not come back again.