"...never wanted to wake up" means "wanted to stay asleep" or "wanted to keep sleeping". Sometimes it's used to indicate that a person wants to die. But it depends on the context (the sentences before it and after it).

但愿长醉不愿醒

Excuse me, but I do not quite understand what do you mean with your question : ' What does '' never wanted to wake up'' meaning ? ......... Maybe you want to ask : ''What is the meaning of this phrase : ''never wanted to wake up'' ??? ..................... Am I right ????

means he/she enjoyed sleeping, perhaps had a nice dream, and did not wish to wake up.

If they are sleeping, it means they do not want to wake up. If they are dreaming, it means they are enjoying the dream and do not want to stop dreaming.