...Technical analysis, at its core, is the analysis of market forces of supply and demand which represent the overall market sentiment. In other words, the price of an asset is a reflection of the opposing buy and sell forces and these forces are closely related to the sentiments of traders and investors (mainly fear and greed). ...
TA is the analysis of prices (and volumes) with no real regard for the underlying causes. Nowhere are the underlying causes of a head-and-shoulders pattern explained (because they don't exist). Nowhere can you find any real studies showing that a MACD signal actually predicts anything (because they doesn't). Nowhere can you find explanation for the contradiction of a double top turning into a double bottom (because there is none).
TA is really just astrology for traders. TA is a pseudo-science based on fantasy and confirmation bias, but dressed up to look like science. There are no scientific or mathematical bases for TA. There is no empirical evidence that any TA techniques actually work.