I had beads - nay, rivulets - of sweat on my brow. Why wouldn't it open?
You guessed it: I was installing RAM in my new Mac mini. I avoided Apple's $425 price tag for a 1 GB upgrade (from the meager built-in 256 MB of RAM), and bought generic RAM for $200. I also watched Other World Computing's very clear video of how to use a putty knife to crack open the mini case.
Perhaps I was too sanguine. I'd slipped the knife in, and starting cracking. But the noise was terrifying. I watched the plastic bow and thought, "This just can't be right, regardless of what I'd heard."
I persisted. I nicked the bottom of the case a bit, but after wiggling it this way and that and hearing awful ship's-rigging-collapsing, nightmare-tree-falling sounds, the case released its burden and allowed me access to the beautiful innards. I'd wrestled with the giant clam and snatched its pearl.
Well, I snatched a 256 MB memory module. I put the new 1 GB module in, sealed her back up - just a little worse than re-sealing a Tupperware-brand container - and fired the puppy up.
Happy as a clam, it booted.