Sorry Folks...
I've had my GC since 1995 and I've NEVER had it on me! It sat in my desk drawer the entire time. The only time I take that baby out is when I needed for my N400 application purposes (fingerprinting, interview, etc.).
People loose wallets daily, you want to chance that?
No need to carry on you 24/7 if you're in the 50 states full-time, regardless what the USCIS says, unless you travel internationally frequently.
Trust me, no immigration officer will ask you, "did you carry your GC with you daily since you got the GC?" during your N400 interview!