The best marriage advice I have received is: Write the good in stone and write the bad in sand.
Some people do the opposite. They dwell on every mistake, every shortcoming, every argument as if they’ve chiseled these past incidents on stone and are ready to recite them on demand from memory.
But all the good, all the acts of kindness and love are never on the forefront of their mind in the same way because the good hasn’t been registered in the same way and hence has been lost to the sands of time.
This is also good advice for personal interactions and life in general. Part of being a grateful person is to overlook and forget and to dwell on the good as much as possible.