When I restarted working with my kanban board in January 2019, I did not remove any of the items in the backlog part of the board.  Last week, I had to move to a different cubicle last week, and I took all the backlog post-it notes off the board with the intent of adding them to the board in my new cubicle. On Monday, I started creating new post-it notes for my current work, and decided to not look for those old backlog items just yet. I rapidly built up a new backlog (as I captured every task I thought of (step 1 in Getting Things Done)), but have been completing tasks at a much quicker rate than in early January (completed at least 10 tasks a day through Wednesday). I think not having those old items has helped me to feel more motivated about completing tasks on the board. Whatever the reason is for the increased productivity, it feels good!