1. continuously concern yourself with something/someone
obsess over something/someone
To 'obsess' means to constantly be concerned with something or to think about it continuously, sometimes in a way that causes concern or has repercussions. You can obsess over a topic and want to know everything about it. If you obsess over a person it could lead to worrying behaviour, this is similar to 'infatuation'. Some people can obsess over details, wishing to make everything perfect, others obsess over cleanliness or germs for example.