Do something unproductive today. At least an hour. Maybe more. This isn’t a life-hack to increase your productivity later. That’s not the point.
I don’t even care what you do—as long as it’s unproductive. It could even be fun. Play a video game you’ve been eyeing. Go for a walk. Read that cheap paperback you won’t admit to reading. Hell, just browse reddit for an hour. Just do something unproductive.
Don’t justify it. Whatever you do, don’t justify it. Don’t say “Playing this video game will give me something to talk about with my co-workers”. Don’t say “This walk is exercise and I’m becoming healthier”. Don’t try to justify it to yourself. That’s not the point.
If you feel guilty doing this, that’s ok. Sit with the feeling and it will go away.