in CVX I saved the Calico pistols, the grenade launcher, the BOW rounds, etc, for the tyrant battle on the Airplane. And I left them all in the item box.... Screw me and the helicopter they brought me in on.
in RE3, I was getting all the special weapons from Nemesis, dumb me skipped one of the battles and only had half (Frame) of a STI Eagle 6.0.....
There was also that one time in Spain... Didn't like the music, but there were knives and running and pro mode.. and a bunch of screw ups...