Driving - Third Lesson on the road

Today driving at night time. So tired and cannot concentrate. I felt that my performance was not as good as during day time. I guess the instructor also tired after a long day teaching students that he seems a bit irritated? Or was it I too sensative? Anyway, I got horned today... for driving too slow but not my fault also ma. Night time even more traffic. Damn that stupid driver who horned at me today. Don't he know that he cannot anyhow horn unless to prevent an accident? My instructor assured me that it's just normal. They don't have patience for L-Plate drivers one.