One of the seven habits that Covey details in Seven Habits of Highly Effective People is Sharpen the Saw. One of the ways I keep my skills sharp is to take time on a weekend or evening and do a little hardware engineering, programming. I’ll just want to solve some problem. Recently, I got the urge to do a little bit of Java again because a friend is learning Java and she had questions. I’ve also been teaching one of my granddaughters electronics. It’s good exercise for the brain.