energy retrieval question

[Jason]

can one use energy retrievel to pick up only one energy card, from the discard pile? pretty sure the answer is can't.

 

[PokePop]

If you have more in there, you have to take 2 Basic Energy.
If you only have one, you can take one.
This is the exact same ruling as Fisherman.
That ruling can be applied to ALL cards getting cards from the discard pile.
Do as much as you can, as long as you do something.