I am one who thinks a lot! Are you laughing at the obviousness of that statement??! It can be harmful if I am feeling guilty or worried about something. I read this helpful advice today (It may seem so elementary to some but I need to apply it!!):
"You can't stop thinking about a pink elephant by trying not to think about a pink elephant. Try it if you don't believe me. Try as hard as you want not to think about a pink elephant. Are you trying really, really hard not to think about that pink elephant?...
"The only way not to think about a pink elephant is to casually think about something else instead, gently drawing our attention to the birds outside the window, some fascinating problem at work, or the love we feel for a child. When guilt has become a futile obsession, distraction is the best course. Simply make a mental note that says, 'tempting guilty thought,' whenever irrational guilt starts sloshing around. Receive the feeling instead of resisting it, label it as nonconstructive noise, and then gently, smilingly turn attention to other things. This approach is far more effective than horrified insistence the we must not think guilty thoughts" (Wendy Ulrich, Forgiving Ourselves: Gettting Back Up When We Let Ourselves Down, pp. 168-9).