I’ve noticed that sometimes I’ll get a blade that will last for 3 months and others that will last for a couple weeks. The average for me is maybe 6 weeks with daily use. Maybe 10% in a bag are at one extreme or the other. I don’t think you can conclude much from an N-value of 1 sample.
You're absolutely right. I taught statistics to grad students and have written a GP statistics package (microstat7.com) so appreciate what you're saying. I didn't mean to imply that there was any statistical validity to what I'm saying here. I was just wondering what others thought.