i've just googled norco half life it says 4 hours. how often where you using and how long? were you getting sick if you left it too long between doses?
i ask cos i used heroin almost every day for a year without getting a habit. it didn't go well for me in the end though i don't advise it. i got a habit when i started smoking in the morning. before i was using in the evenings so had almost 24 hours between doses. the half-life of gear is 12 hours so it makes sense that with daily use and the very odd day off it wasn't building up too much, hence not getting ill. once i never let more than 50% get out of my system between using i got a physical addiction straight away.
though the methadone kinda throws that cos i guess that was daily and i think its half life is 24 hours, but as cj said a month isn't long it can take some dedicated long term use to get a physical opiate habit. though once you've got one you'll get ill super quick i can't use even a tiny bit once now or i'll be ill.
also with a long half life withdrawals will take longer to set in, and i get super drowsy at the start of a rattle so that may be why you slept like a baby.
either way get off the kratom it's gonna draw out or create pain needlessly.
