A consequence can be unintended without being unforeseeable.

Unintended is a claim about what you wanted, not about what you could have known. Plenty of harmful effects were available to anyone who looked for a few minutes and simply nobody looked, because looking was not required and the plan was already appealing. That gap is where most avoidable damage lives.

Before committing to something, spend ten honest minutes listing how it could go wrong for people other than you. Say the answers out loud to someone. Foreseeing is a practice, not a talent.