Learning something that takes a long time is hard. A big reason why that is, is because you have goals set up for yourself and these long term goals usually don't have a definitive stopping point. There's no one to say good job at reaching this point or really how you should know to move on. You may reference others to figure out whens a good time to move on or say you've reached a landmark but that doesn't stop the paranoia if you've truly accomplished what you want.
Learning for me is hard as I'm sure it is for others as well. Learning how to draw is by far the hardest task I'm willingly bringing to myself besides maybe working out but even then I handle physical tasks better than mental ones.
-TakuAmazuki- venting to the void at the end of 2019.