Something a little different

I am always telling you all about my dogs; how cute, how good, different behaviors and basically why they are the best dogs in the world.  Today I'd like to try something different; I'd like to hear from you all.  Now I know if I just say "tell me about your great dogs," I'll get more than I bargain for.  We all think our dogs are the best in the world right?  Just as it should be.  So..................what I'd like to know is; what is the one most important lesson that your dog or dogs have taught you?

After all the comments, and hopefully I'll get some comments, I will add mine.  I can't wait to read this.