Actually, nothing can be truly objective. We're basically limited by what our senses tell us and we can construct models based on this observation. That's not to say we can't create stronger or weaker assumptions, just that we can never 100% know what is going on beyond the confines of our sensory organs.
Mind can't be "right" or "wrong." We can only perceive as much as our minds allow us to.
A bee's life may seem mundane and boring to us since we're a much more advanced species, but that is basically all the bee knows. And similarly, the decisions of the less intelligent may seem completely irrational to the more intelligent, but that is because to the less intelligent that seems like the most rational course of action.