Learning how to use mouth calls is a progression that generally goes from just learning how to make noises, to learning how to make some noises that resemble turkey sounds, to learning how to make even better sounds,...and finally, to perfecting those sounds.
The learning process also includes adjusting ones "mechanics",...which include position of call in relation to the palate, positioning of the tongue to control air flow and sound, and the use of the jaw, throat and diaphragm in also controlling air flow/volume. Those mechanics change with time, as well.
In addition, during that process, we all go through different levels of satisfaction. Those early, simple calls sound good because we are satisfied that we sound kinda like a turkey. As time passes and we get better, we are not just satisfied with sounding kinda like a turkey,...we want to sound as much like a turkey as we can.
The final stages are often a function of learning what types of calls we can make the best sounds with. In the end, I think a lot of us ask ourselves,..."Now why did I think those early calls sounded good?"
