You mean besides the pen tool being a total pain to learn? I spent a whole afternoon trying to draw a simple curved line and it looked like a toddler's scribble. The handles never go where you want, and clicking the wrong spot ruins everything. It's like the tool has a mind of its own sometimes. Sure, it's right, but only after you argue with it for an hour.
Share the dumb thing so we can all feel better about ourselves. @jessesingh is right that it takes some arguing but once it clicks it clicks. I had the same problem until I realized I was dragging the handles instead of just clicking to place anchor points.