That is because you don't have any thing to do that can puzzle your brain. Try to buy some puzzles and patiently solve them. Do activities like cooking, go for a walk, swim, do math calculations. I prefer painting or puzzles cause it helps me take a break from my mental stress, family issues and many more. Don't date so that you could have a partner date so you could find your better half. If she left you that means she didn't see how much love you had for her. She was blind for your love and care for her. You will find someone better.