I didn't notice how ridiculous catch-up exp was.

During champ select, I was jungle and my top didn't want to lane so he went jungle after throwing a tantrum. Our support had to mid and our mid had to top and adc solo lane. I fought with my top lane for jungle camps and yet, we were able to keep up with enemy jungler's exp. At this point, we stopped fighting (around level 3-4) and went full force, grabbing dragon, stealing enemy jungler's camp, running two man ganks on all lanes. If catch-up exp wasn't as high as it was, I don't think running double jungle would be a viable strat.