I hate driving when it rains, it's like everyone around me decides to pull 20km/h off the speedo just to compensate for their lack of ability to be able to read the traffic and possible hazards that may occur ahead of them. Turns into a snail race.
Then you have the people in the overtaking lane that don't move from it for the whole stretch of the highway , so you naturally tailgate them a little bit to let them know "hey, I have somewhere to be" so they start brake checking you to make you back off. Sometimes I wish I had the time to follow these people home and pour a cup of sugar in their petrol tank.