You cannot have your cake and eat it 英文諺語
You can’t have your cake and eat it (too) 魚與熊掌不可兼得
Once the cake is eaten, it is gone. It can be used to say that one cannot or should not have or want more than one deserves or is reasonable, or that one cannot or should not try to have two incompatible things; you can’t have two desirable but contradictory options – you have to choose.
There is a sentimental part in most people that wants to make a good experience continue for as long as possible, and then to have good memories that last forever. It’s only human nature to want to be comfortable and happy, and “having your cake” can actually come in many forms. There is a promise in having the metaphorical cake that is sometimes broken when the actual cake is eaten. There is disappointment involved in the realization of any dream. Dreams and expectations are abstract and ideal, whereas experiences are very real. As you think about a cake, it is as moist and flavorful as your imagination can make it. You can change the flavor from vanilla to chocolate and back in a heartbeat. But once you’ve mixed up the ingredients and they’ve been in the oven for 20 minutes, you’re going to have a cake that conforms to the recipe you actually made. There’s no going back short of baking a brand new cake.
“You can’t have your cake and eat it – if you want more local services, you can’t expect to pay less tax.”