@cameronb67 Not a dumb question at all, and glad you're considering it! You can generally wear N95s for up to 40 hours before you need to replace them; what decreases their effectiveness is the straps loosening (which is also what makes them so much better than any other kind of disposable mask). The straps loosen a bit each time you don and doff them.
In our family, we're willing to reuse them several times for outdoor use or indoors when viral levels are low. However, for anything high risk or when levels are high (like now...see
https://biobot.io/data/), we will often toss them after one use indoors (again, due to strap tension, not due to the masks themselves). I'll reuse them at home for changing litter or working on the car or whatnot, and similarly, I'd have no issues reusing masks outdoors (e.g., for high AQI days or for allergies) for weeks.
Personally, I'm a preschool teacher in a building filled with hundreds of children and dozens of adults, almost none of whom mask and almost all of whom are sick every single day, so I take no chances and replace my N95 (a VFlex standard size) every single day.
