昨夜梦难留今夜难有梦
[zuó yè mèng nán liú jīn yè nán yŏu mèng]
It literally translates into 'Yesterday’s dream hard to stay tonight hard to have dreams'. It conveys a sense of sorrow or yearning from last night and expresses worries that similar sweet moments won't occur again in future nights. It could also mean the owner had insomnia at both yesterday and tonight, implying some anxiety state in real life.