"It takes a whole new skill set and lots of deliberate work to make the switch." This is very much true. Right now you are managing code. As a manager you'll be managing people, your managers, and in many projects. Managing people can be very difficult. You not only deal with the business day to day issues but you'll have to deal with some of the life problems of the people you manage. Some people love it and others dislike it. It's not a higher level of writing code. It's just different and requires new skills.

BTW, young managers can be at any level of the management structure. It's very possible that your new boss as a manager could be younger than you.