Everybody teaches that what you think about comes about. What they base this inane untruth on is the bad things that you somehow seem to “make happen” by concentrating on them through fear.
And although the fear-based “manifestation” is true a lot of the time, the “positive” manifestation happens only as accident, if ever.
The basis of the “negative manifestation” is called self fulfilling prophecy in psychology, which is a pseudo-science based on observation and theories.
Most of the theories in any discipline are wrong, so nothing special about psychology. What is special is how pseudo religion, law of attraction made it a law… churns my stomach. And we all ate it in our fervent desire to gain some control over our lives.