What you cannot escape as a coder
One of the inevitable things in coding is you will encounter countless errors (both known and unknown) and bugs, and they could be frustrating sometimes.
The most vulnerable part of web programming to me so far is the JS file part. Sometime I just have no idea which part of it got crashed with other files, and then I will try to copy some scripts (which should be bug free) from others to see if it works or not, and most the time it will crash again and again. I will then use most of the time understanding what’s happening all there rather than writing codes.
But that makes sense. Unless you are clear with all the concepts and flow on every items and components you write, you may just summing up all the minor errors along the way you do the project and then all of them explode at once when they become too complicated.