A Lesson in Self Control

The other night we had a lesson on Self-Control for Family Night. At the beginning of the lesson, I handed each of the kids a large marshmallow. Here's how the conversation went.
Mom:Now kids, before you eat your marshmallow I want to let you know something. You can eat the marshmallow right now...WAIT! Not yet! You can eat it right now OR.....you can wait for 5 minutes, and if you can wait, then you will get ANOTHER marshmallow.
Bella at this point was about to pee herself if I didn't let her eat her marshmallow so I felt like I had better make sure she understood.
Mom: Do you understand Bella? You can eat your marshmallow right now...WAIT! WAIT! OR you can wait until this timer goes "BEEP, BEEP, BEEP!" and THEN, THEN you will get TWO marshmallows to eat. If you can wait. And not eat this marshmallow. Right now. Do you understand?
Bella: (nods head)
Mom: So are you going to eat it right now?
Bella: (nods head yes)
Mom: Or wait for the timer and get another one?
Bella: (Looking at marshmallow longingly) I want to eat it right now!
Mom: Ok Bella, that's your choice, you can do that...WAIT! Not yet! Just know that if you wait for the timer you can have another one. Two. Ok, so anyone who wants to eat their marshmallow go ahead, and anyone who wants to wait for another marshmallow, put it right here in front of the timer.
At this point Payton and Katrina get up and place their marshmallows in front of the timer. Out of the corner of my eye I see Bella coming over and she places her marshmallow reluctantly next to the others.
There is a large bite taken out of it.
I try to contain my giggles as I set the timer and start the lesson. At this point my lesson is in vain because Bella is asking every 10 seconds..
"Can we eat it NOW!"
"Now??"
Then the little stinker at one point says: "BEEPBEEPBEEP,BEEPBEEPBEEP,.....Did you hear that mommy?"
Finally after 5 agonizing minutes she got to eat her 2 marshmallows in a single inhale.
Lesson...learned?