Mistakes aren't failures.  When it comes to eating people tend to beat themselves up for overeating.  They think, "Shame on me.  I shouldn't have done that.  It was so stupid.  I'm going to get so fat."  This sends them into a shame spiral that often ends up in further eating for comfort.  

Remember that everyone overeats sometimes.  Even the most normal, intuitive eaters do it occasionally.  The key is to view it as an opportunity to practice self-compassion and gain some wisdom.  

When you discover you've overeaten get curious and ask yourself some questions:

• Was I hungry when I started eating?
• Why was I eating to begin with?
• What was I thinking and feeling at the time?
• What type of food did I eat?  Why did I eat those particular foods?
• Did I eat  mindfully or distracted?  Was I connected to my body?
• Was I paying attention to my fullness levels while I ate?
• When did I realize I had eaten past comfortable fullness?  
• Why did I eat past that point?  
• What could I do differently next time?

The answers to these questions will give you a lot of data.  Don't miss the opportunity to gather some Golden Nuggets of wisdom.  Collect them like treasures.