This reminds me of my younger days, @iyimoga. Except the disagreement was not with my sister, it was with myself! I remember procrastinating on studying, and then drinking coffee to stay up late to study and finish writing papers. Part of my brain would say, "Ah, it's great to study when it's quiet." And another part of my brain would say, "But I'm so tired. Maybe I just need to rest so I'm fresh for the morning!" I'm still not sure which part of my brain was the smartest.