Not because I want to take it slowly, but because I have a lot on my plate and my natural tendency is to "unflatten time", fast-forwarding in my head all the different plays and things to do. Some of these will only apply in a year, but here I am thinking about them and worrying about them now. Worse still, I sometime make decisions related to these future things and as you all surely know, decisions are paid for with a mental toll.
So I dial back, focus on the immediate thing in front of me and remember that nearly any progress is made of trivial, tiny chunks.
Having an effective system of writing stuff down is key to that approach - your future ideas and various pending tasks need to spill into writing instead of lingering around your head. When you have a good writing system you can trust, then you can free your mind to focus on the now.