Why can't my mind stop thinking when I'm trying to sleep?

Here try this. When you lie down to go to sleep think about the number 100, then start counting backwards most people fall asleep before they even hit 50.

Getting away from the busy outside world gives your thoughts room to surface. Personally it helps to listen to music or watch TV before bed to give me something light to think about rather than cycles of obsessive thoughts.

This is a result of your cluttered brain and you should try thinking of one thing only and go to sleep.

Your mind is thinking on a regular basis. Throughout the day, you get distracted enough to not fully pay attention. During sleeptime, it's quiet and usually dark ... Which leaves you with nothing to hear but your thoughts. And you being alone with your thoughts doesn't always have to be destructive or mind-wrecking, sometimes you need to listen to yourself.

I believe that we tend to think even more at night time because it's so quiet that you lose yourself to your mind. I think that some music would help in stopping that, still depending on your mood. If you are feeling down, depressed, distressed,anxious etc.. I believe that talking about what you're thinking instead of bottling it up would help you sleep.

The reason that the mind started to think is first because you created a ripple or an event that happened in your life that causes you to think and puts more efforts into it. This was what happened in people with anxiety where they felt anxious that something is going to happen to them or someone is thinking about a stressful situation that they don't know how they get by. If you felt this way, please talk to someone or to a professional counselor that can get you the help needed.

Seems like days are long and busy enough. But when I lay down to sleep, my mind won't stop thinking. So I end up tossing and turning until such time sleep finally claims me. Then it's the same thing over again.

Because you are not worried about other stuff that you usually do during the day so your brain is focused on what you are thinking.

I am sorry that you had to go through this. The mind is restless by its nature. It has the capability to jump around from one thing to the other. Trying to sleep is a difficult thing. You need to first analyze why you aren’t able to fall asleep. Maybe something is really bothering you and making you feel depressed/anxious. In such cases, it would be wise to visit a registered mental health professional who can help you. Practicing meditation and mindfulness will be a good addition to your treatment. They help you to gain more control over yourself.