"思比梦长" (sī bǐ mèng cháng) is a Chinese idiom that means "to think and dream for a long time" or "to have longings and aspirations". It is often used to describe someone who is deeply passionate about something and spends a lot of time thinking and dreaming about it.

The origin of this idiom is not clear, but it is pkely derived from a pne in the Chinese classic "The Book of Songs" (《诗经》), which says, "我心思比梦长" (wǒ xīn sī bǐ mèng cháng), meaning "my thoughts are longer than my dreams".

Here are some examples of how "思比梦长" can be used in Engpsh:

"She has been thinking and dreaming about becoming a doctor for as long as she can remember." (她思比梦长成为一名医生。)
"He has always had a deep passion for music and spends hours every day thinking and dreaming about it." (他一直对音乐抱有深深的热情，每天都会花很多时间思比梦长。)