Why you should write often

 Any creative activity, that is activity that requires more than passively absorbing data is very hard. That is because by default it requires far more energy to create something than to just consume or destroy as the case may be. 

Writing is a creative activity, and it is hard to do. It doesn't matter what you are writing, either words, codes or equations. Bringing stuff out of your mind is very hard, and I believe that it is the core part of what we call general intelligence because it activates the processes that utilize knowledge rather than just passively absorb and store it. 

You could augment memory by using a notepad to store some of the facts that you record, but it is harder to augment the ability to create something new or express your solution to some problem, which is what all true creativity is about. 

Writing also requires some of the highest level of focus you can summon, for instance writing computer programs or mathematical proofs require the largest amount of energy your brain can summon, because it is some of the highest level activity your mind can participate in. and this goes to other forms of art or design, like painting or engineering drawing. 

Like every muscle if you do not train your ability to output information it will atrophy, so like you exercise every other muscle of the body you should also exercise your ability to output information whether it is in the form of writing or other things that utilize your hards or any other part of your body that participates in creative output, yes there are people without hands that draw with their mouths or feet, which is such an amazing ability.

ONE MASSIVE OBSTACLE: Too much self-judgement.

Sometimes we refuse to engage our creative side because we are too self-critical. We think we are not good enough and don't have much to offer etc. YOu will not get better in a static sense, you have to actually take action by doing to get better no matter how rusty you are in the beginning, you just have to keep doing and not judge your output too harshly.