IMO confidence is vital, but perhaps not in the traditional sense - think more of it as a healthy dose of self-assuredness. Create a life plan and follow it - I've found that strategy attracts the type of people I want in my life (friends, colleagues, partners). At 18, I was still in high school and really hadn't had quality relationships, but when I got into university, everything changed. My plan was to focus on academics, fitness and being active with various clubs on campus - apparently that's an attractive combination :)