Hayden Panettiere’s memoir isn’t all trauma and family drama — ’cause she also shared one chaotic Hollywood memory involving ‘shrooms, “Scream 4,” and David Arquette making a very questionable movie-night choice.

The actress said the whole thing went down back in 2010 while shooting the movie when she, her bestie Allie, and a bunch of twenty-something crew members went glamping at a property rented out by Neve Campbell. That’s where she tried mushrooms for the very first time.

Hayden admitted she had no clue what to expect going into it — but felt safe doing it around close friends she trusted to keep the weekend stress-free.

Yeah … the timing was terrible. By that point Hayden says she was already deep into the haze of her first ‘shrooms trip — and within minutes, the movie’s nonstop gore, corpses, violence and carnage made her feel like her eyeballs were about the spout blood.