It’s not the Tryptophan, It’s How Much We Eat.
Despite popular belief that turkey has a particularly high amount of tryptophan, the amount of tryptophan in turkey is typical of most poultry. There is also a myth that plant protein lacks tryptophan; in fact, tryptophan is present in significant amounts in almost all forms of plant protein, and abundant in some.
Tryptophan is a routine constituent of most protein-based foods or dietary proteins. It is particularly plentiful in chocolate, oats, dried dates, milk, yogurt, cottage cheese, red meat, eggs, fish, poultry, sesame, chickpeas, sunflower seeds, pumpkin seeds, spirulina, bananas, and peanuts.
That explains a lot, actually.