Board Thread:Questions and Answers/@comment-24276288-20140423170801/@comment-24276288-20140424030453

TheAdfeng wrote: Once you learn how to do something, you can always "forget", but it can come back to you just as easily. Use it or lose it, they always say. It's just like calculus, history, or any other subject. If you don't keep using it, you'll forget it. But, luckily, it's easy to pick it back up.

but it's hell out of difficult for someone to forget calculus