If it helps I do the same thing and will, no doubt, continue as the years go by. Just two days ago I was cutting pieces and muttering to myself that it was going to take all day if the cuts didn't go more smoothly. Put in a new blade and what a difference. I don't know if it is that we think that they are not dull and just have encountered tighter woven fabric, or that it couldn't possibly be time for a new blade, don't want to be a quilter who wastes perfectly good blades or just stupidity. For my part I believe it is a combination of all of these and will, once again, make a mental note to change the blade more often.