I know. It's easy to sit around watching mindless television for three months while you're on summer vacation, but doing that definitely won't help you when you get back to school in September. I've got some ways for you to work your mind in small ways so you won't feel so overwhelmed at the beginning of the semester, while also giving you something to do during the summer.
I'm not talking about reading a book every day about the laws of thermodynamics. Just read small things. Maybe read that book you've been wanting to but just haven't gotten to. Or read some magazines or comic books. Or even your shampoo bottle. As long as you're reading something, it keeps your mind up to par.
2. Do crossword puzzles or word searches
You can probably find some in every magazine or newspaper you have. If you prefer online games, Crossword Quiz is actually really fun to play because it includes current interests and is really easy to play. Studies have shown that doing crossword puzzles do, in fact, help stimulation of the brain and exercises the muscles.
3. Learn an instrument
Or if you already know one, learn another. You can work on your coordination and helps to keep your brain going as you learn more about the instrument itself as well as learning the music.
4. Learn a new language
I'm not saying become fluent by the end of the summer, just work from being a beginner to intermediate. If you know you're going to be taking a language next semester, try learning a little bit, so you familiarize yourself with the language and be a little ahead of the game. Try Duolingo for some interactive language learning.
5. Watch some educational shows
You can watch PBS documentaries if you want, but check out some things on YouTube on things you find interesting, not something you think your teacher might. If you're not sure what you're interested in, but are cool with learning about random facts, check out Adam Ruins Everything on TruTV because I've learned more about the history of different holidays and traditions than I have anywhere else.
Remember, do things you would enjoy. This isn't meant to be a summer session of school; this is trying to keep your mind working, but in fun ways. Try new things and do them at your own pace. It's summer, after all!