I studied CS topics to open up a whole other side of software. After being a web developer for so long, I was ready to expand to other areas.
There are many technology distractions. New frameworks, languages, and tech pop up every day. How does someone keep up?
With so much out there, you may find it best to specialize in one area you really enjoy: front-end development, database administration, dev ops, security, as a few examples. There are many available areas of specialization.
Companies like Google want people with wide, shallow knowledge, but deep knowledge in one small area. It’s called a T-shaped skills: http://blogs.ptc.com/2014/12/03/why-engineers-need-to-develop-t-shaped-skills/
Choose a project or two that really interest you. Then dig in and get very familiar.