tell me, why i can't i dream of nicer things?

This is the 4th dream/nightmare ive had in a span of two weeks about snakes and other creepy animals. Ewww. I dreamt they tied us up and put us in tanks with snakes {oh the horror!} and bugs and wiggle things. i neaaarly died. Then we escaped but they found us and told us we were being pranked. Heelllllo. I felt so angry. Even when I was asleep. And I woke up feeling angry.
on the same note, yesterday i dreamt i was eating a hugee salty fishball, and as I was about to bite into it, my mum called. and i woke up. shish. :/ now im craving salty fishballs.