One thing my years in the airline and travel industry have taught me is this a smooth trip doesn't start at the airport. It starts with the decisions you make weeks before you ever pack your suitcase. I've seen people miss cruises because they flew in the same day. I've seen vacations ruined because someone didn't check their passport expiration date. And I've seen cheap flights end up costing more because of baggage fees, change fees, or impossible connections. These days, I'd rather pay a little more for peace of mind than save a few dollars and spend my vacation stressed out. Travel is supposed to give us a break from everyday life, not create more headaches. What's one travel lesson you've learned over the years that you'll never forget?