Also make sure to do some less cognitive ones as well. Get certified in SCUBA, get your motorcycle license (take the MSF safety class), play a new sport. All these even if you never plan to pursue it after the cert/license.
The more the diverse your experiences and knowledge, the more interesting and fruitful leaps in abstraction you will be able to take.
I've done MSF which is incidentally GREAT as general driver's training. I've also got a US Sailing Basic Keelboat cert somewhere. Sailing has also had a big impact on how I think - learning to deal with forces much greater than you is very worthwhile.
If you live near a ski area, pickup the cheaper weekday season pass and do night skiing twice a week until you can handle the black diamOnds with ease.
The more the diverse your experiences and knowledge, the more interesting and fruitful leaps in abstraction you will be able to take.