It is important to do something new every now and then.
You might ask “Even if I love what I do?”.
The answer is Yes.
Because it is quite natural for us to fall into seemingly subconscious boring lapses of momentary non-existence even while doing the things we so much love.
When you do something new every now and then you free up your mind from that preoccupied form so you can think more clearly and better appreciate what you do. It opens your mind to new perspectives on which you can become more creative and productive.
Now to the first question, what if you really love what you do. Then take up variations of what you do. One of my favorites is to take up small one week or two week projects by dedicating some time daily.
Since I love writing I take up small writing projects that force me to think differently in both content and style. In that process I have found variations of my love that I later decide to spend more time on and take up seriously. Something I would not have done if it was not for this small projects.
A few examples are Poetry Translation, Flash Fiction and so on.