Take every memory of anyone you’ve ever loved (including your first crush, your momma, your worst girlfriend, that girl from the summer on the beach, the one that got away, the one you left behind). The good and the bad, but importantly only the ones that evoke a strong passionate emotion.
Insert your wife’s face into these memories, try to imagine all the sides of her personality, all the shades of her colour in all the different glimpses of light.
Visualize the memory: the hike she didn’t take with you that August, 2 years before you met her, up to the top of Mt Baker, the romantic picnic she wasn’t there for, the lake skinny dipping in the moonlight that wasn’t with her. The nerdy girl in 6th grade who held your hand in the dark at the planetarium.
If these all feel right, if she fits, if she could have actually been every woman you’ve ever loved, then you’ve found your soulmate.