You are the rare exception.
I agree it’s best to test it but there are so many reports of bad batteries testing ok because the shop is using the old style testers that don’t work on newer batteries. I use a solar ba-7 to check CCA capacity.
However it’s still true that at least 90% of the time of the battery is more than 3 yrs old and you have strange electrical issues, it’s the battery. So if you can’t get it properly tested replacing it has good odds.