While they might not know what is coming up, they do have the ability to remember what they once were. Which I think is a beautiful analogy to how we experience the world too

https://www.sciencefocus.com/nature/butterflies-caterpillar-memories

The transition from caterpillar to butterfly via a soupy pupal mashup remains one of the greatest mysteries of the animal kingdom. During metamorphosis, body parts are liquified and then reorganised, but the ability of memories to survive this process was unknown. That is until scientists trained caterpillars to avoid the whiff of ethyl acetate by pairing the chemical, often used in nail polish remover, with a mild electric shock.

When the larvae turned into adult moths, most continued to avoid the odour, suggesting that moths and butterflies may indeed remember some of their larval experiences. Yet another reason to be kind to caterpillars.

With such a relevant username (and instance): Did you know you would someday transform, @LadyButterfly@piefed.blahaj.zone?

That's very cool!

I think first they wake up with an urge to puke a cocoon all over themselves.

Imagine if one day 12 yeah old you went to sleep, then woke up a month later and were a humanoid bat monster who drank blood through a straw built into your face, were SUPER horny, and then died when it got cold outside.

What do you mean “imagine”?

So butterflies are caterpillar vampires?

Human aren't the only animals with blood.

This doesn't answer the question, but some Japanese kid discovered that butterflies retain memory from when they were caterpillars even though their insides turn to goo during metamorphosis. I find that so cool.

Fucking hell yeah brother! What a way to live! Hard and fast baby!

How the hell do you test for that?

I think they ran a current through leaves of certain plants that shocked the caterpillars. The little dudes eventually started avoiding them after being zapped so many times. When they turned into butterflies, they would still avoid it. I think the study even showed that the memory carried over to the butterflies' offspring (dunno for how many gen though).