I've heard being able to speak two languages keeps your brain healthy and prevent dementia and other cerebral diseases caused by aging. Today I learned a bit more specifically how the brain works. When people switch languages, dorsolateral prefrontal cortex in their brains is improved and the part plays a large role in problem solving, switching between tasks, focusing, and filtering unnecessary information. It shows learning English makes my brain healthy and active. I'm in the middle of enhancing working memory, not only for English but for everything I try in my life, so the scientific basis always reassures me that I may have better retention already.