Advice on confidence

Hi all, I have had a couple of interviews, case studies presentations and assessment centres, but I have never received an offer for the roles I want. However, I have applied to some jobs/internships I don't like nor want, just to get some experience in the recruiting process, and I normally perform quite well, as I am not nervous about the outcome. I was wondering if not caring is a key aspect in developing confidence when interviewing or presenting case studies? Or maybe those other jobs have an easier recruitment process.

Thanks beforehand!