I'd say anything where weight, shape, and fragility are highly variable. 

But if I'm traveling, I usually cram my clothes into a bag without folding them.

> I'm a pretty excellent at bagging groceries.

Is it confined to groceries or does it transfer to other forms of packing?

Undisciplined

AskSN

What is the obscure skill at which you are ridiculously talented?

wackster

I'm a pretty excellent at bagging groceries. 

Also forgetting media - movies, tv shows, books. I don't completely forget them. It's more like I forget how to retrieve the memory until enough context is provided. Quite a few times I've been halfway through a movie only to realize I've already seen it because I can predict what happens a little too accurately.