Study Skills: 20 minute blocks

Brief Wakeful Resting Boosts New Memories Over the Long Term Link In other words, just relaxing after learning a new concept (rather than studying another concept striaght away) boosts long-term memory. Paper abstract from Psychological Science.
Why studying in 20 minute blocks is key
Keep a record of your distractions throughout a few days
YouTube -1 hour from psychogical lecturere Dr. Marty Lobdell.