This was in fact one of my big learning experiences in mechanical work. As a kid, my bike was running rough so i took it apart, cleaned oout all that yucky/dir

This was in fact one of my big learning experiences in mechanical work. As a kid, my bike was running rough so i took it apart, cleaned oout all that yucky/dirty grease from the bearings using WD-40, and then reassembled it all only to find it was even worse than before. Only a few years later did I learn that wd-40 is a terrible lubricant for bike ball bearings. You can see a similar effect with standard skate bearings used in fidget spinners - most bearings come pre-greased with a fairly high viscosity lubricant. If you spin the spinner, it will slow down quite fast, but if you take the bearing apart, clean out all the grease, and reassemble it, it will run wicked fast and long. Until some dirt gets in, at which point, grease would have worked better.