First RAW Project: What's the Biggest Newbie Blunder?

Alright, folks. Raj here, Focus Puller by trade, but trying to broaden my horizons a bit with post these days. I'm looking at cutting a passion project myself, a short documentary shot on an AMIRA, maybe some B-roll on a V-RAPTOR XL. I'm going full RAW for the first time, not just ProRes. I've been digging into things, and a lot of guides mention the usual pitfalls: underestimating GPU power, not using proxies, forgetting about proper storage... all valid, I'm sure.

But I'm wondering, from veteran DPs, editors, or anyone who's been through it: if you had to pick one mistake, the single most common and costly blunder newcomers make when attempting their first truly RAW project from start to finish, what would it be? I'm trying to preempt any major headaches down the line. What's the one thing that bites beginners the hardest?