Total myth, your body absorbs what you eat, it doesn't stop at a magic number.
That being said, some research indicates that protein synthesis tops out at 20g per serving, which would mean that you should eat AT LEAST 20g of protein for each meal, but you can absolutely consume more than that.
More important, IMHO, what is your total protein intake for the day? Is it below 1g/kg of bodyweight? Then you should eat more, 'cause apparently the ideal is closer to 1.5-2g protein/kg of bodyweight. Go figure.