But the speed at which people are reporting their magnets losing strength makes me think they're either using low-quality magnets, or their brains getting used to the sensations and tuning them out. I think if mammals had an evolutionary purpose for sensing magnetic fields, they'd already have methods for doing so. From recollection I think dolphins have this trait and use it to navigate.
or nerve damage from having a magnet just under the surface, several of the people here said it hurt to bump them
Some magnets lose strength from concussions and higher temperatures. A very strong magnetic field can also damage the magnet. That said, motors with permanent magnets have quite good performance properties and are pretty energy efficient.
And if your magnet fails, you can always revitalize it with an external magnetic field.
> Neodymium magnets are the strongest and most permanent magnets known to man. If they are not overheated or physically damaged, neodymium magnets will lose less than 1% of their strength over 10 years - not enough for you to notice unless you have very sensitive measuring equipment.[1]
So while they apparently do degrade, it still makes me wonder what these people are doing to markedly reduce the power of their magnets considerably over just a few year.
[1] K&J Magnetics - FAQ https://www.kjmagnetics.com/faq.asp