Pokemon Blue
FYI the internal cartridge battery that’s used to save your game is probably either dead or nearly dead!
A multimeter should show the battery at 3.25v. Anything less and it could die any day. Changing the battery isn’t too difficult, but it requires soldering.
This is my favorite tool set used to take the one screw out to open the cartridge, to check the battery.
https://www.retromodding.com/collections/tools/products/repair-tools-set
https://en.wikipedia.org/wiki/Motte-and-bailey_fallacy
Today I learned! :)