You are describing "buyer's remorse." You can research it by using that search term. It's most common with younger, first-time buyers and it doesn't always mean that the house was a bad purchase. It's common to feel a let down after any big decision in life and is usually a temporary feeling. The forms you sign at home closing are legal agreements. In the U.S., buyers are usually restricted by the contract in terms of what situations permit them to get out of the agreement to buy (such as an undisclosed structural or insect problem, for example). Simply changing one's mind is usually not accepted as a reason to refuse to honor the contract, although states vary and some allow a very short (a few days) period. If you have a mortgage, you have also signed a legal contract with a bank separate from the purchase contract. You owe mortgage payments whether or not you still like the house. You can always sell it. But the best way to avoid buyer's remorse is to be know exactly what you are looking for in a house, and to get a full home inspection from a professional so that you don't discover surprises after moving in.
