It was a little of both for me. I certainly wasn’t sure I’d get in, but I thought I stood a decent chance. I had put a lot of prayer into my decision to go to medical school, and I felt that if God intended for me to go, He would make it happen, so I didn’t bother with applying widely. For that same reason I wasn’t worried about not getting in because I would have taken it as a clue that a career as a physician was not what God had planned for me (at least at that time).
I’ve always been sort of an “all or nothing” type person. I applied to 1 college, 1 medical school, and I’m considering the ultimate Hail Mary move of only ranking 1 residency program (I think it would work out, but at the same time I’m not sure it’s the wisest thing to do). I do most of my narrowing down way early. I researched lots of colleges and narrowed my list down to 2 before I even applied. I visited those places, hated one and loved the other, and realized I only needed to apply to one. When it came time for medical school, there was only one choice for me. I had considered a state school as a backup, and probably would have applied there if I didn’t get in in the early decision pool, but I didn’t have to.
My advice to you would be to not apply widely just because someone told you you had to. Research schools you’re interested in. Don’t apply to any school you wouldn’t be happy going to for the next 4 years.