Most chain checkers tend to be conservative, causing people to replace prematurely.
However, maybe you have a fluke chain checker that goes against the norm?
I use a chain checker as a preliminary check because I KNOW it's conservative. IF it shows "worn", then I get my hands dirty.
Measure you chain with a ruler and calculate an actual number. basically you are calibrating the checker too, so you know what it really means.
I measure a 3' section of chain to give 3X the resolution of measuring a 1' section.
I use the 1" & 37" marks of my tape measure to avoid any error from a bent/uncalibrated end piece.

You didn't mention miles & riding conditions. If you ride in wet conditions with water/grit getting tossed on the chain you'd naturally expect a shorter life than clean/dry conditions.
IF you are heavy & mash, you may putting some hellacious stresses on some relatively small surfaces. If you never get out of the saddle, you'll probably get longer life.

You also didn't mention any cleaning/lube regime.