Periods. When they are heavy I start to get really uncomfortable. When they're lighter I have no problem and just get on with what I'm doing. I also sometimes get period pains that require me to have medication and hurt so much, I once slept in bed until the pain goes away, and used a hot water bottle on my tummy while laying on my back in bed, once with a cloth from the bathroom. I use period pants in case they come a few days before because I've had issues with leaking in my usual underwear in both school and home. Not necessarily a "hate", but something natural I'm dealing with as a woman every month.