Is it wrong to want to be a professional musician when I'm older?

The only thing I really want to do for the rest of my life is be in a crappy underground band with some friends and earn enough money to survive. Do I have no chance of achieving this since I want it? So many “rockstars” out there say that they never expected to be doing what they are doing and that it just kind of happened. They say that they dreamed of it but never though about it seriously because they though for sure it could not happen.. Does this mean its wrong to want to do this since your life never turns out how you want it or imagine it? I don’t care about money or fame or anything..I could go on and on about my good intentions for why I want to be in a band..love of music, inspiring other girls, and the whole life of living in a van and just making music with friends. I’m scared this can never happen since I just assume it will! (I try so hard not to assume that!) but I can’t see myself doing anything else. What do you think, musicians?