The Butterfly Garden

I'm spending a lot of time stalking the butterflies in my gardens.  They've been very patient with me as I shove my camera through the flowers to get a picture.

Red Admiral who waited for its close up
A female monarch.  She looked a bit shiny which made me think she was freshly "hatched"
Eastern Tiger Swallowtail letting me get up close while it was drinking
Monarch munching on milkweed
I'm loving how trusting these creatures are with me.  Does anyone know if butterflies have memory? I'm wondering if they can learn, and then recall, that I'm not a threat.