Losing track of time

I've rolled about 10 or 11 times in my life and everytime was at a festival. I've always had beans from the dark net and I usually take half then another half an hour later (200-220mg each). The effect of this to me makes me lose track of time and time just flys by. Is there a reason for this? This year at my next festival I'm getting actually crystal MDMA so I can weigh my dose out more effectively and control how much and when I take it.