I wouldn't know what to do with the OOMouse's extra buttons, either. 18 buttons is more than I could remember, much less reliably click. For a few years I've

I wouldn't know what to do with the OOMouse's extra buttons, either. 18 buttons is more than I could remember, much less reliably click. For a few years I've been using mice with "only" 2 extra buttons, mapped to CTRL and ALT. Because they are close together on the thumb side, it's easy to click either one or both together. This is especially nice for gaming, allowing access to the C-, M- or C-M- equivalents of a key without moving the keyboard hand. This matches office application use cases such as selecting text and operating on it, whether both hands can act in parallel.