Being a Catholic School Boy, I've always experienced a bit of Sunday-night dread about Mondays. ("I'm not prepared for work/school." "It's the beginning of another long week." "I just wanna get away from all this.") Now, when I wake up on Monday and feel a little bit ill at ease, it means I'll feel better in a couple of hours, and much better by Monday night and grateful that I made it through another Monday.
When I go to bed/pass out drunk on Sunday night and then wake up on Monday with a hangover and all the horrific thoughts and feelings that come with it, it means that things have only gotten worse, and that my whole life is falling apart all around me.