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wake up on the wrong side of (the) bed
To be in a particularly and persistently irritable, unhappy, or grouchy mood or state, especially when it is not in line with one's normal disposition. I'm sorry I snapped at you earlier, I think I just woke up on the wrong side of the bed today. Jeez, the boss has been in a really bad mood all day. I guess he must have woken up on the wrong side of bed!
wake up to (something)
To become alert to or aware of something, especially something that needs to be recognized as a problem. You need to wake up to what's happening instead of ignoring the situation. If this country doesn't wake up to the hatred that's among us, we're going to have a bleak future.