Dear Abby: How can I stop my sleepless nights?

Dear Abby: I have been happily married to my wife for decades, but something has me really frustrated. No matter how stressful her day may have been — family, politics, money — my wife can fall asleep the minute her head hits the pillow. I am the total opposite. I end up not sleeping because I don’t understand how anyone can be genuinely distressed and so easily fall asleep. Any advice?