Student or Learner
Does this "catch" mean "difficulty"? Is it a common idiom?
2) To begin with, what is an asset? Simply speaking, an asset is anything that puts more money into your pocket on a regular basis. The traditional definition of an asset was a bit different because people regarded an asset as anything that could be turned into money. Let me give you an example. Look around your room. Is there anything that has some money value? Probably you have more than you think: a computer, TV, a cell phone, and so on. However, here’s the catch. Although you may believe anything of some value can be an asset, it is actually not an asset as long as it belongs to you. Why is that? It is because it does not add any money to your pocket until you sell it and get some cash in your hand. In fact, the same principle is applied to the cash in your wallet. In other words, if the cash is sitting in your wallet, it doesn’t put more money into your pocket.
tIt's a common idiom. 'Catch' means 'snag' or 'disadvantage'.