This should not be surprising to anyone who has a preschooler. They're also way better at problem-solving than most people expect, it's just that you often don't
want them solving their "problems".
When my kid was 18 months old, we had gated him off from a playroom with a bunch of toys used by his older brother that were not baby-safe. We had a DoorMonkey [1] placed up high, about 5 feet tall, so that only adults could reach. My kid gets a chair from across the room, pushes it next to the door, climbs up on top of it, unlatches the DoorMonkey, pushes open the door, climbs down from the chair, enters the playroom, looks at me, and says "Bye!" At that moment my wife gets out of the bathroom, sees the tableau, says "____? What are you doing?" and my toddler says "Uh oh."
[1] https://doormonkey.com/
When my kid was 18 months old, we had gated him off from a playroom with a bunch of toys used by his older brother that were not baby-safe. We had a DoorMonkey [1] placed up high, about 5 feet tall, so that only adults could reach. My kid gets a chair from across the room, pushes it next to the door, climbs up on top of it, unlatches the DoorMonkey, pushes open the door, climbs down from the chair, enters the playroom, looks at me, and says "Bye!" At that moment my wife gets out of the bathroom, sees the tableau, says "____? What are you doing?" and my toddler says "Uh oh."
[1] https://doormonkey.com/