What is the most common problem riders have?"
What do you think it is?
I've answered this question many times in many ways but have never been truly satisfied with my answers or felt they were completely informed, researched and stamped with the Good Housekeeping Seal of Approval. Things like that bug me to no end-I'm supposed to know these things! Don't ask yourself that question, though. Don't ask what your own most common rough spots are. Don't do it. I'm warning you; it's a dead end. The apparent number of answers is ... aw, just Google it.
More often than not, if you ask a rider for some outstanding experience he'll tell you about a crash or near-crash. That's fine for wowing your mates, but how about looking at the moments of amazement; of new and fresh awareness you've had while riding; of breakthroughs? That's the right attitude with which to start a ride.
Think of the times when things went well. Like a moment when you finally figured out a turn. Realized the throttle wasn't going to kill you and that it was actually your friend. A time you turned quickly enough to avoid something. Stopped target-fixating on the outside of a turn and went where you wanted to go instead. Went into a corner fast enough to catch your breath but didn't panic with the brakes. A moment you felt secure at a steeper lean angle than ever before. A corner where you were getting signals that "all is well," renewing your faith in tire technology. A time you turned-in at the right place and knew you had a sweet line. A start when you got the clutch and throttle perfectly coordinated. The day you began getting your gear changes smooth. A situation where you saw a disaster unfolding and avoided it. Or when you really felt in control with complete clarity; detached but still fully in command. Those types of things.
It's long been a pet peeve of mine that riders put too much attention on things that aren't happening. Trying not to crash. How can you try not to do something?! Trying not to crash sounds like a preventative procedure, but situations always require a positive series of control inputs to save your bacon. Avoiding trouble requires pre-observation, planning and positive action.
Here's a little trick to accelerate your learning curve: Once you identify an error that seems to occur over and over again, try making that error on purpose. Hopefully, this isn't crashing. Try some other aspect of riding that's not quite so dramatic, like smoothing out your gear changes or getting the bike on-line earlier in the corner. Getting a bad line? Try bad lines on purpose. Botching your gear changes? Botch a few. Stabbing at the brakes on corner entry? Stab at the brakes on purpose. Do it wrong a few times. You may be amazed at what you learn.