In Year 2 I had brown boots, Shane had black and one day we just swapped because we realised that was the only way the teacher could tell us apart. It always came in handy with school work because we would share the workload a bit. There were probably a few occasions. Not as far as tests were concerned, but there were a few assignments one found easier than the other. We used to share the workload a bit.
Kids can be cruel.
I think we got a lot of confidence in being together. We used to have a bit of tension build up occasionally. But that would be about it. No grudges were held whatsoever. I think its just something that comes from living together for so long.