Without thinking you may also drink too much caffeine both as coffee and in soft drinks. Or it may be those over-the-counter cold/decongestant tablets. Unless you go and talk to a physician about your diet and lifestyle, identifying the precise cause of your insomnia may not be at all easy. One of the insomnia myths is that "older" people are more likely to have difficulty sleeping. "Old" for this purpose is the arbitrarily selected age of fifty-five years. In reality, this simply confuses cause with effect. As people grow older, they are more likely to develop minor aches and pains.