I pushed my brother off the bed once. We were just out of toddlerhood and in our parents' bedroom. We were on the bed, and he was putting on his underwear and had his butt sticking in my face. I wondered to myself "what would happen if I pushed him?" Curiosity got the better of me so I gave his butt a little nudge. He fell hard on the floor and started crying. I instantly regretted it and felt guilty for a long time. A part of me used to wonder if that contributed to his mental illness.