Why do many people easily "make small profits and suffer big losses" in a bull market?

Many people believe that a bull market is an opportunity for wealth to soar, but there is a very counterintuitive viewpoint: the main reason most investors lose money is not because of a prolonged bear market, but because of the bull market.

In a bear market, it is likely that there may not be short-term profits, but there is a high probability of making big money in the long term.

In a bull market, it is likely that there may be significant short-term profits, but there is a high probability that it will end up being a wasted effort in the long term.