We use this when we want to talk about a situation in which a person wants something to happen. However, there is a strong possibility it won’t happen, so someone else encourages them to expect that it won’t happen. Here are some example sentences:
Don’t tell Sue you can take her to Disneyland if you’re not sure. I don’t want you to get her hopes up.【不要告訴蘇，你可以帶她到迪士尼樂園，如果你不確定。我不希望你讓她抱太大希望。】
A: Valerie said she’d help me move.
B: Don’t get your hopes up. She always agrees to help people, but then she doesn’t.
【Source：http://goo.gl/YDVzRz】
【圖： 別對致命的完美抱太大希望 - 那是需要條件的 ：http://goo.gl/fqp9ME】
