In my ‘20s I traveled for 6 weeks through Europe with one backpack that I carried myself.  For our week-long honeymoon, my husband and I took one large suitcase between us.  Just over 2 years later, my husband, 11-month-old daughter, and I had an overflowing luggage cart that held 2 large suitcases (overweight), 2 stuffed-to-the-brim carry-ons, and a car seat.  In hindsight, we should have added our playpen to the pile, since the hotel-issued crib for that trip was pretty wobbly.