think about doing something
例：I’m thinking about changing my job.
think about someone/something
例：She often thinks about her childhood.
just thinking about it
例：Just thinking about the exam makes me nervous.
think carefully about
例：You should think carefully about your future plans.
think seriously about
例：They’re thinking seriously about moving abroad.
have a lot to think about
例：After the meeting, I had a lot to think about.
something to think about
例：His words gave me something to think about.