You don't have to think about it, it's wonderful to go a whole day without caring about your period! Thank God for not having to use tampons!
It doesn't leak at night as pads do, it's cheap and environmentally friendly, but mainly that it doesn't dry out my mucus membranes and doesn't contain bleach and pesticides that I don't want anywhere near my uterus.
Congratulations on your 3 year anniversary! I recently started using a menstrual cup and the only thing that I'm sad about is that I didn't start with this sooner. It's amazingly great in every way!