Ha ha! Very good indeed! And very true.
It must be said, that while often publish charts with lines and things on them, in practise I just eyeball everything. Sometimes I draw a line or two to e.g. confirm a support level over a long time or try to estimate the breakout point in a triangle pattern, but I prefer to work lineless.
Why I do draw lines for posts is to help with my explanations of market activity and to try to get the reader to visualise what is happening in my head. But once again, you're right, take those lines too literally or think that they are the future, and you're screwed.
Except for very long-term trend lines, now those I trust!
Nothing wrong with drawing lines if they're support or resistance or showing market structure like triangles, penants etc, especially if you have some kind of confluence system that relies on them. That's just normal business for most of us.
It's more the people that have to draw 10 moving averages, 3 fibonaccis, an elliot wave and an ichimoku cloud on each chart (just to try and impress the scrubs with their complicated looking charts)