It's hard to know what you're not seeing when you don't see it. Again, you're lacking the experience. You're lacking the ability to pick up on indicators and have that interaction with travellers, which is really what you want those experienced officers to be there for.
I've seen officers who are much better than I ever was, who are able to identify someone who's here for ill intent with three questions and a look. You watch them work, and you think it's almost magic—they're that good. To get that good, it takes years and years of being able to pick up on indicators, ask the right questions and know what travel patterns are. That's the kind of person you want working at the border, not someone who's working their first job with three weeks of training.
