The Zeigarnik effect says that people remember uncompleted or interrupted tasks better than completed tasks.

Three thoughts:

• If you want to learn or remember stuff, it can help to take short brakes mid-flight. Your brain will continue to process the information you studied. This might be why the pomodoro technique works so well: because your brain is repeating the topic, it will retain better.
• If a topic is still circling your brain, it is easier to pick it up again. This is why you could experiment with not completely finishing your work at the end of the day. Because your brain is still working on bits of it, it could be just what you need if you are a slow starter in the morning.
• If you want to really detach, you need to make sure to close your open loops. Closing open loops is one of the big topics in Getting Things Done. As long as you know there is still something that needs to be done and you have not resolved it, by either fixing it or putting it in a system you trust, your brain will keep reminding you.