It's really disappointing when a TV show you invested a lot of time in has a plot twist that doesn't make sense or is unnecessary or is just simply disappointing.
For example, maybe you had watched all seven seasons of Pretty Little Liars only for A.D. to be revealed as Spencer's long-lost British twin, which came out of nowhere.
Or perhaps you were mad after waiting nine years to see Ted meet and fall in love with his wife on How I Met Your Mother, only to find out she died and the point of Ted's story was actually to explain his love for Robin.
Or maybe you absolutely hated when Luke discovered he had a daughter on Gilmore Girls because it was totally random and another unnecessary obstacle for Lorelai and Luke to overcome.
