I'm shocked to find how much I have improved over the years. I had problems with cartooning and linework. I honestly believed I did awesome with that Dash in 2011! (The image on the right was completed in 2013, even though I uploaded it in 2014)
For those who does not have such a contrast in their art, do not worry. Artists are like trees, we all grow a little different. I've seen artists progress much faster than me, and slower, and they all became masters!