If it doesn't fit on my keychain it doesn't get EDCed (urban environment). That being said, my keychain is kind of huge.
Stuff on my keychain:
Leatherman Squirt
Tiny Doug Ritter flashlight
P-38 can opener
CountyComm peanut lighter
Large fishing swivel
Hair elastic (for DW/DD1/DD2)
AAA LED flashlight (EOS brand)
Pill case
Kershaw small locking folder (don't remember model)
Assorted keys
Other than those things, the only other item is my TracFone and cash. When out and about on weekends and after work I add either a Sig P938 or a S&W 351PD but I can't have those at work.
In most cases my truck is within a block and it's ready for any apocalypse Hollywood has come up with. My office at work has plenty of food, water, a radio, and toiletries stashed away to keep me clean, fed, and informed for several days.
I used to EDC a Maxpedition bag with EVERYTHING in it (bug spray, 1st aid kit, silcock key, assorted tools, duct tape, etc) but I never needed any of that stuff so quickly that going to my truck was a problem. Heck, if I weren't a pyro I'd dump the lighter but I can't quite drop below a caveman-level of preparedness (fire and something sharp).
-Blast