The Fairy-tale Aspect

I realize that I wasn't clear about where Once Upon A Time fit in with the story. If you watch the show you probably caught on, but this will clear things up for those of you that haven't...

The coolest part about working on a story for Puck would be the mysterious woods and the magic. I am quite partial to the idea of using a magic potion. It is like a reverse love-potion. It would cure Puck of his unattainable love in a very lighthearted way. The effect would be to forget all memories of the person you were in love with. This way you would never suffer over it. You would not be bothered by the memories, or the image of the person that you are in love with.
I can totally see Puck having his mischievous side come out after drinking this potion because it makes you completely oblivious when you were so preoccupied and obsessed before.
I think it would totally be an OK rout to go because Shakespeare used magic and even a love potion before in Midsummer Night's Dream.
Here is where Puck talks about it.

On the ground

Sleep sound:

I'll apply

To your eye,

Gentle lover, remedy.

[Squeezing the juice on LYSANDER's eyes]

Plus if this is the back story for Puck, it would add dramatic irony when Puck uses potions on other people later in his life in Midsummer Night's Dream, because that is exactly what he did, only he doesn't remember of course.

This kind of potion was actually used in Once Upon A Time, which is where I got the idea.
This clip shows the effect of the potion. I can really see Puck becoming apathetic and adding to his joking attitude as a result of this potion.
(Just to clearify the clip: Snow Wight was in love with Prince James (charming) but he was being forced into an arranged mariage and therefore they couldn't be together. That's when Snow decided to forget him.)

Here is another clip that explains more about how the potion will function. (Snow makes a deal with Rumpelstiltskin to get the cure for a broken heart.) - Watch out Rumpel is very creepy!