The main and common mistake is that players overestimate the strength of a pair of jacks. This is a really good hand preflop, but it becomes very vulnerable on the flop. Moreover, it is extremely difficult to amplify such a combination. These two factors indicate one thing: you should not invest all your chips in this combination. Preflop you will often be called back with an ace, king or queen, and any occurrence of such cards on the flop will put you in an uncomfortable position. It is almost impossible to get out of it, tied to the bank with high rates. Therefore, even not preflop with JJ, you should not act too aggressively.