wishful thinking 单凭主观愿望的想法；一厢情愿；如意算盘；痴心妄想；不实际的幻想

【例句】
This, I am sorry to say, is almost entirely wishful thinking.
我很遗憾，这几乎完全是一厢情愿的想法。

It is wishful thinking to expect deeper change under his leadership.
指望在他的领导下发生更深层次的变革简直是痴心妄想。