Our family spent the holidays in the hospital, on purpose. Home from college, our daughter needed surgery to correct a congenital circulation problem in her leg, so we pre-scheduled to have the remainder of the holiday break for her recovery.

The situation was neither life- nor limb-threatening, but it was surgery, involving five hours under anesthesia, plus the other mysterious risks of such a grim business.

In my 18 years as a father, I’d never placed my child in a surgeon’s hands. I watched myself, the way I acted and reacted, and the things that surprised and tested me. For any parent, or anyone with a loved one going under the knife, here are the lessons I learned.

Lesson: The go-ahead decision is hard. Sure, you’ll find yourself bathed by voices of reassurance. We live in a lucky age when medical miracles abound. Surgery is routine; don’t we all experience it eventually? And the safeguards, so many safeguards. The risks are low, aren’t they? Please reassure me again.

During the pre-op meetings, I scrutinized the surgeon and anesthesiologist with X-ray intensity. Did that guy get a good night’s sleep? Is he stewing about something in the other (less important!) parts of his life that might steal his attention? Did his hand just shake a bit? What if he’s addicted to painkillers like TV’s Dr. House?

It felt like sending her off to kindergarten, or summer camp, or her first solo plane trip, 30,000 feet out of my reach — all moments of letting go and placing trust in others. We’re left standing there so helpless with no choice but to trust.

Our daughter’s surgery was serious enough to require ICU attention afterward. Lesson: Just because the staff hooks up a dozen monitors to your child’s body, it doesn’t mean they expect a vital organ to fail. Repeat that like a mantra. You’ll need to.

There were complications after her operation. Lesson: Everything has a side effect. When things went awry — blood pressure, nausea, anemia, allergic reactions — medications were administered, and those had side effects. Side effects have side effects.

I once thought of medical people as Mr. Fix-Its. Problem? Solution! Leaky pipe? Replace the seal! Blown circuit? Install new wiring! A one-two sequence.

But that’s wrong. Medical people are like pilots. The plane — the human body — is kept flying by a hundred highly interdependent controls, like on a Boeing 787 dashboard. Fine-tune one dial and a red light blinks unexpectedly. Yank a lever to correct it and bam! — the patient loses altitude.

We parents watch the plane from the ground as it pitches and rolls. We shout skyward, “Is that normal? Is everything OK?” Sometimes the pilots in their white coats are too busy to holler down understandable answers. We jump up and down and wave our arms and slowly come apart.

But the staff at the Medical Center of the Rockies understands what parents go through. Visitors are welcome 24/7, so for all six days in the hospital, our daughter was never alone. Lesson: A patient needs an on-site advocate. Even the greatest flight crew, backed by a million dollars of monitoring technology, cannot be as attentive and caring as a family member sitting alert in the aisle seat until the plane lands safely.