How the unseen impacts the seen

Sometimes I am working in a file and am having a hard time getting the text and images to line up right.  That always means there is some hidden code somewhere in the file that is preventing me from doing that.  All I need to do is locate and remove the offending code.  But first I have to remember that the problem is the code, and sometimes I may spend hours trying to fix something before I remember, it is hidden from me.  I cannot see it with my eye, I must find where it is hidden.  Kinda like life.