Scientists at the Max Planck Institute of Neurobiology have worked out why it’s so much easier to re-learn something that has been learnt before, even if it feels like you’ve totally forgotten it.

I find this very comforting, because there are so many things I’ve spent countless hours learning, but have subsequently forgotten. I always thought, or at least hoped, that all that effort wasn’t completely wasted.

Fuller details are available in the press release, but to cut a long story short, the reason is this: When you learn something, structural changes occur in the brain. Neurons send out axons and dendrites to connect with other neurons and allow the exchange of information. The connection is called a synapse. When we have learnt something, these connections are fully functional, but when the information is no longer needed, the connections are ‘disabled’ and we forget. However, the connection remains and can be easily reactivated.

I guess an analogy is that learning something for the first time is like grabbing a power cable, plugging the appliance into a socket, and turning on the switch. Forgetting is like turning the switch off, and re-learning is like turning it back on.

So, go forth and learn, it’s just like riding a bike!