Technical analysis can give you a false sense of 'knowledge' - when you may only be picking up patterns in randomness. But it's very seductive in its certitude.
Gold : If the 'store of value' argument is obvious to you, it's also obvious to a lot of other people. The price of gold tends to balance out the two camps : Anyone who sells you gold believes (naturally) that the price is higher than can be justified (vs. other assets). Gold can certainly go up and down from here. People also used to believe that houses were a fantastic store of value ('everyone has to live somewhere') - that was only 6 years ago.
The typical trader's wisdom is that if a taxi driver (or some other version of 'the man in the street') offers an opinion about a 'sure thing' - run in the opposite direction. Currently, taxi drivers love gold. A few years ago, they had friends flipping condos. Before that it was internet stocks, etc...