Expression: Bite off more than you can chew

To bite off more than you can chew is to take more responsibility or risk than you can manage. I like this expression because it's very graphic: you can imagine it!
It's generally considered a negative situation, because you are overwhelmed. On the other hand, sometimes biting off a little more than you can chew means that you feel ambitious and want to do a lot of things, which can have some great results...
It's fair to say that this spring I bit off more than I could chew, and some people have felt the bad effects of this. For example, earlier this week I completely forgot about a class, even after my student and I had talked about it that very morning! Not good! My closet is disorganized and I really need a haircut. My gym bag is full of dust bunnies. I haven't seen certain friends in a very long time. All of these are indicators that I bit off more than I could chew.
In any case, summer is here and I'm beginning to see the light. What about you? Have you ever bitten off more than you could chew? What happened?

P.S. This post is dedicated to Anna, Carmina, Sandra, Edi and Adri, Vera, Harriet, Alena, Erica and Jonathan, Vassilis, Socrates, my parents, and many others. I'm sorry and I really appreciate your patience and understanding!