Is Jadzia Dax immature?

I was watching the episode called “Meridian” of Star Trek Deep Space Nine. It occurred to me that Jadzia Dax is immature.
Here is why I believe that. She falls in love with a guy, and decides to go live with him. It doesn’t turn out that she can stay with him, and is depressed that she has to wait 60 years to be with him. This is coming from a woman who is over 700 years old. What is 60 years to her?
However, even if she had one life, she has a great life that she loves. So why should she be depressed that she has someone who she can love in 60 years? To me, that seems like a great treasure. To know that you have someone who loves you, that you can meet again and be happy with. How lucky we are, to have those opportunities even if it isn’t on our personal timetable.
Immaturity to me is when you pout about things that don’t go your way, and you ignore all the wonderful things that are going your way. How lucky most of us are!
