I was hoping someone would start a thread like this.

Do you mean, by saying, "I will get a blow job from Jennifer Aniston" over and over and over again, do I think I can bring it into being?
Not though magic, no.
But, can we take an timid, insecure person and use affirmations like, "I feel confident" and "I believe I am brave" and stuff like that, over and over again, and can that help change how that person feels about himself?
Yes.
Now, if you have a goal you're after, like, a certain nice house, you can say to yourself "I will own that house" as a means of boosting what you're already doing to work toward that goal. You can use those affirmations to help keep on on track and focused.
But can you say "I will have that house" and do absolutely nothing about it, and reasonably expect it to happen?
Of course not.
Look at it this way...
How reasonable would you assume me to be if I told you that I pulled a tooth from my head, put it under my pillow, and said over and over, "The Tooth Fairy will bring me $1".
How many time would I need to affirm this before I brought it about?