My thoughts do not mean anything.

This idea applies to all the thoughts of which you are aware, or become aware in the practice periods. The reason the idea is applicable to all of them is that they are not your real thoughts. We have made this distinction before, and will do so again. You have no basis for comparison as yet. When you do, you will have no doubt that what you once believed were your thoughts did not mean anything.
This is the second time we have used this kind of idea. The form is only slightly different. This time the idea is introduced with "My thoughts" instead of "These thoughts," and no link is made overtly with the things around you. The emphasis is now on the lack of reality of what you think you think.
This aspect of the correction process began with the idea that the thoughts of which you are aware are meaningless, outside rather than within; and then stressed their past rather than their present status. Now we are emphasizing that the presence of these "thoughts" means that you are not thinking. This is merely another way of repeating our earlier statement that your mind is really a blank. To recognize this is to recognize nothingness when you think you see it. As such, it is the prerequisite for vision.
Close your eyes for these exercises, and introduce them by repeating the idea for today quite slowly to yourself. Then add:

This idea will help to release me from
all that I now believe.

The exercises consist, as before, in searching your mind for all the thoughts that are available to you, without selection or judgment. Try to avoid classification of any kind. In fact, if you find it helpful to do so, you might imagine that you are watching an oddly assorted procession going by, which has little if any personal meaning to you. As each one crosses your mind, say:

My thought about ---- does not mean anything.
My thought about ---- does not mean anything.

Today's thought can obviously serve for any thought that distresses you at any time. In addition, five practice periods are recommended, each involving no more than a minute or so of mind searching. It is not recommended that this time period be extended, and it should be reduced to half a minute or less if you experience discomfort. Remember, however, to repeat the idea slowly before applying it specifically, and also to add:

This idea will help to release me from all
that I now believe.

- Jesus Christ in A Course in Miracles, Lesson 10