I always heard of people... when they ask my what strings i use i say... 0.009 and they say... well... i've "graduated" to new strings... which i never really understood..

but today i was jamming an old hubert sumlin tune " killing floor" and my 0.009 broke... wasn't even hard on the strings... i play guitar everyday (always my squier thesedays), for about an hour - 2 hours... should I "Graduate to heavier strings" or just keep replacing my 0.009. Lately i've been breaking the 0.009 alot..