You can spend a fortune hardening the perimeter and still get walked through the front door by someone who simply asked nicely. The uncomfortable truth of security is that the strongest link in most organizations is the technology, and the weakest is the person reading their email at the end of a long day.
Attackers know this, which is why so many real intrusions don't start with a clever exploit. They start with a message. An email that looks like it's from a colleague, a vendor, or the help desk. A request that feels routine — approve this, click here, confirm your login, the invoice is attached. No firewall inspects intent. No patch closes the gap between "this looks legitimate" and "this is legitimate." Social engineering skips your entire technical stack by targeting the one component that can be talked into things.
I used to think of security as mostly a technical discipline, and I've had to widen that view considerably. Your controls matter enormously, but they defend against the attacker who tries to break in. They do very little against the attacker who convinces someone to let them in. Against that, your defense is people who are aware, who feel safe slowing down, and who know it's normal to verify a strange request instead of rushing to comply.
