You can practice anything you put your mind to. If a skill is something of value to you, practice will make you better at it. Here are a few things I have been practising for a long time. 

I graduated with an undergraduate degree in Mechanical Engineering. Over the past half decade I have worked on many projects and co-curricular actives alongside my studies.

Guitar is another skill I have been perfecting over the years. I have been performing and teaching guitar and developing my playing for the last 14 years.

I also enjoy studying abstract strategy games like Shogi, and Igo. Swimming is another activity I can do for hours no matter the time or day.