Most of the techniques mentioned in this article relate directly to the way our brain makes associations and forms memory. Learning something is a two step process: retaining the new information in the brain and then forming association between that and the things that we already know.
I have observed that trying to recall something that I have learnt ensures I retain the information instead of simply getting the illusion of learning something.
Mixing topics essentially allows you to create new associations in the brain about the topic. The stronger the association about a topic, the more you retain the information. Another technique that works really well is trying to apply a new topic to your own life. By relating new information to things you already remember, you create the pathways to remember and retrieve certain information.
Edit: link - how long term memory works:
http://education.purduecal.edu/Vockell/EdPsyBook/Edpsy6/edps...
- Storing a bike is a problem in cities like NYC and SF due to space constraints
- Electric bikes offer faster commute option than a regular bike but are more expensive to buy
- Bike theft is a really big problem in cities
- It's very convenient to have the option to ride a bike somewhere without worrying about carrying it around