If you read the same books, watch the same shows, go to the same places, eat the same foods, do the same things every day–it stands to reason you’re going to think the same thoughts every day.
Thoughts are products of our experiences, a rearranging of things we already know. So if you want some new ideas, you’d do good to throw some new ingredients into the pot. Your characters, worlds and plots are always going to be narrowed to your limited experience of reality, no matter how good your imagination is.
In the 2015 film Room, we see some of the world through the eyes of a boy who’s lived his entire live trapped in a single room. Even with the best mind in the world, being hindered by such a lack of experience would guarantee that any story he imagined would pale in comparison to the reality he has no idea of.
We all live in ‘rooms’ of our own making who’s walls are are the length and width of our experiences. Your characters can never enjoy a dish you’ve never heard of, climb a mountain you don’t know exists, or feel a feeling that you can’t comprehend.
Push your walls back whenever you can. Every new thing, whether you personally enjoy it or not, is an opportunity to expand your capability for imagination.