Paper or Plastic?

I'm one of *those* people.
You know, someone who takes their own bags to the store.
When I forget my bags and I just happen to be picking up 1 or 2 items I simply tell them a bag isn't necessary. Usually that's not a problem.

Went to Target. (they offer their own brand of reusable shopping bags btw)
I had to get some more Benadryl for my dog, itchy butt, and a loaf of bread for lunch tomorrow.
Conversation:
*girl starts to put stuff in a bag*
Me: Oh I really don't need a bag for this.
Girl: *stunned look* ooh...
*shuffling in bag for debit card*
Girl: Are you SURE? *puzzled expression*
Me: *uncomfortable giggle* Yea, I'm sure, it's no big deal.

I drop the box of Benadryl in my bag along with my debit card, pick up the loaf of bread and walk out fearing that security is going to tackle me at any moment.

It's so bizarre to me that they don't see to understand the concept of "I don't need a bag, thanks" or "Could you please put my purchases in the bag(s) I brought?" I wonder if they even know they sell reusable shopping bags?

I guess Whole Foods has spoiled me, I get to donate money to charity every time I take my own bags. Talk about easy Karma! Target could take a lesson.