Like the picture says, sometimes success means fail and sometimes fail means success. What I'm trying to say is that sometimes it is more interesting to see our characters make poor decisions than good ones, just as long as they feel the consequences of their actions.
What makes TSTL characters so maddening is that everything turns out okay for them. Someone bails them out. The hero rescues the heroine from her stupid decision and no one calls her on it. She never realizes the error of her ways. Even worse, her impetuous and foolish behavior is praised as brave. This makes me want to leave a permanent forehead impression on my desk.
In real life, people do make bad decisions or act without thinking, but they have to live with the consequences. Failure can lead to personal growth and for characters, that leads to win and awesome! Isn't that what we hate the most about Mary Sue characters? If she is beautiful and sweet and a rocket scientist who speaks seven languages and knits blankies for orphans in between composing piano sonatas--well, where is the drama. Of course she will succeed. Ho hum. On the flip side is someone so flawed that I just can't bond with her at all, but that's another rant for another day.
In my current WIP, my heroine makes a bad choice and conceals information in a murder investigation. She thinks she is simply protecting herself but it becomes harder and harder to maintain the falsehood. The small bit of information she hides becomes increasingly important to the investigation. Finally, she must own up to her actions and live with the consequences. She finally triumphs by making smarter choices.
So lets hear it for failure and stupidity. Huzzah! Don't they make life grand?