While learning something, we go through three phases.
The first phase is where we are constantly making mistakes because we are new. Everything that we encounter seems to be new and difficult, and we spend time consciously putting things together, watching out for patterns and navigating our way towards better understanding of the basic principles. We go through this at a new job, while learning a new language, while making a new friend, while working on a PhD thesis, or anything else.
The second phase is where we start to get comfortable, and develop associations that makes it easy to remember to do things the right way. As a consequence, we make fewer and fewer errors and perform better and better.
The final phase is one of mastery. This is when we reach a stage where we don't have to consciously think of what to say or do next. It becomes second nature to us. We can still get the job done after a few mojitos.
It is obviously great to be in the final phase. If I'm in this phase as a blogger, I can turn on my laptop every evening and half an hour later, I'll have drafted a post of good quality that I can publish. Being in this phase frees up a lot of time to do other things, because we are now spending lesser and lesser time learning and practicing things. We are in free-flowing execution mode.
But, the down side of this is that mastery doesn't last.
All the fields that we are in are evolving. What the audience wants to read changes over time, and a writer has to evolve what she can create to match this. Or she will be outdated over time. Similarly, a footballer has to keep improving his skills to always have a trick up his sleeve to surprise the opposition.
And when we are in the phase of mastery, we tend to not do the things that we were doing in the first and second phases of learning, which is to pay conscious attention to what we are doing with the aim of improving the way we do it, and to practice what we know well and practice even more the things that we do not know well.
When we don't do these things, we do not learn and we do not improve.
This means that we will see a peak when we hit the mastery phase and then a plateau for a while and then a slope downwards to outdated.
It is especially hard to go back to doing things that we used to do in the first and the second phases after coasting through the mastery phase for a while, because we have filled up our time with other things that need our commitment.
While it seems it is ideal that we should reach the mastery phase of any skill, it is a lot more beneficial to stay in the first two phases while continuing to improve upon our performance.