I have some trouble breaking up this example sentence from WaniKani vocabulary 幽霊.
“Let’s skip school and go to the arcade today. YOLO!” “I don’t think so. I see ghosts all the time, so I believe in a world after death.”
In 人生は一度っきりだしな, what does だしな stand for? I suppose だ is the copula, な is “seeking agreement” and し is used as the “listing reasons” particle. Is this correct?
Second question: if the above explanation is correct, is だ mandatory, or can I also say 人生は一度っきりしな?
Thanks a lot!