Disclaimer: I'm saying this for your own benefit, but your comment comes across as incredibly naive, and I would never endorse you as an interviewer with this attitude.
There are life circumstances which one can literally not plan for, and which can derail even the most well-conceived of plans. Chronic illness, war, natural disasters, etc., all come to mind. Give all the examples you want regarding how one might conceivably prepare for one of those things, but it's pretty clear from your opinion that you've never experienced one of these yourself.
On the other hand I'd hire a humble person based on this single trait alone and wouldn't regret most of the time. Humility is an exceptional marker for a good coworker. The best people I interviewed knew their limits and were eager to point them out.
[1] not overconfident, i.e. claiming to know more than they obviously do
People who know what they're doing will over time become more confident.
People who don't know what they're doing will over time become more desperate as they run out of places to fail at.
You could do a lot of work to figure out the difference between someone who knows what they're doing and someone who doesn't. But it's a lot easier to just notice if they look confident or desperate.
Unfortunately, being confident is actually super easy if you're willing to practice it. Much easier than actually being good at anything.
Also unfortunately, being confident is really hard if you don't know how to practice it. And the skill is orthogonal to most other skills. So if you're good at something, it might actually be harder to control how confident you appear to others.
Standard: not saying it's fair or endorsing this, explaining how people think and feel about it.