I dont blame....I have 3 cellphones, all with SIM cards. I switch and change my numbers often, in which makes clients think Im a new guy LOL. Sort of like fishing, just using a different bait (not greatest analogy to use for my clients though lol).
As for sim cards, I would never remove them from the phone for more than 5 seconds because they are too small and easy to get lost. I wish phones had a SIM tracker, in the event that it loses such important piece of memory.