That ass talking about addiction doesn’t understand basic neurology, humans develop stronger dopamine paths to different things depending on a number of factors.
I personally feel like picking the mana rock over the Nettlecyst was a mistake. You already had plenty of mana rocks and the Workshop for acceleration, not to mention Nettlecyst + Cannoneer is too good to pass up. You also can't have too many threats in your deck either, but thats just my opinion.