Sometimes when I fly I'll experience something like a "mental glitch" when I know that at some level, the model has gotten away from me even if just for a second. No one watching would notice it, but I know I messed up. This is often a doubt about orientation.
Right! Now we're getting to the heart of things. I've noticed inquisitive people often lack disciplined concentration habits. I noticed the tendency in myself years ago while learning to ride a motorcycle. I love to observe progress at construction sights, admire the lines of the latest cars, etc. What before was a potential fender cruncher now became a threat to my life. I resolved to either learn better concentration habits or sell the bike before a tragedy caught up with me.
I began to realize that concentration is a limited thing and every task requires a "hit" to the concentration budget. To use a currency analogy, lets say you have $1.00 worth of concentration. While flying R/C maintaining your wings level takes $.25, maintaining field orientation takes away $.30, remembering how long you've been up takes $0.05 and so on up to a total of $.80. A guy walks up badgering you with questions which requires $.20. At this point the smallest unanticipated thing can cause a crash! "Dumb thumbs" is just a way of saying your concentration tried to write a check that bounced.
Experience tends to reduce the cost of each task. Maintaining level wings in a new pilot costs $.80 but probably only costs $.05 in a well seasoned one. Conversely, speeding things up reduces the entire budget. Going from a gentle trainer to a hot pattern plane may cut your budget from $1.00 down to $.50. Fatigue lowers your budget drastically also.
Once you start thinking in terms of a budget you can start to work on ways to spend more wisely. Earlier I mentioned planning each maneuver before starting it. Doing this has the effect of paying much of the concentration cost up front so you take less of a hit to the budget in the middle of the maneuver. Most aerobatic maneuvers can be performed toward sky or toward the ground. Traveling skyward increases your budget by slowing things down, while toward the ground does the opposite. Change-ups in the middle of the maneuver are especially dangerous because they extract an exhorbitant fee on the concentration budget - mental price gouging. A panic situation is the ultimate price gouging.
Individuals also vary in their concentration costs. One guy may only pay $.05 for avoiding stall speed while another may pay $.40 because he's become obsessed with it. So it's important for each pilot to identify their high costs and work the prices down. An interesting side effect of simulators is imbalances in skills that develop. I've recently noticed performing a knife-edge to the left costs me $.10 but to the right costs me $.50 because of the direction I always take off from.
I've found the best way for me to improve my flying is to accurately assess my performance of each flight just after landing making a mental note of mistakes I made and things that went well. By doing this I can focus on areas to improve, eventually freeing up my concentration budget to spend on more challenging things. Without reflection we quickly forget the nuances and return to the simulator to log hours doing things that don't really need work.
I don't mean to sound clinical about flying. It should be fun! But improving concentration will go a long way to reducing the task burden so flights can become more enjoyable, creative and worry-free. With a better budget cushion I tend to fly more relaxed, smooth and precise. I can experiment a little because I'm ahead of the airplane and that's really why I enjoy flying.