If your Dad buys a Lego camper set for you, it comes with a canoe.
You can walk to a nearby stream and put the canoe in the water.
The current will carry the canoe downstream,
as many times as you want! It's great fun!
And because it is summer, the same stream might be completely dry the very next day!
The day before, further up the stream, there might be a little pool that your Lego guy can swim in.
If you tie a piece of twine around the Lego guy, you can throw him in the middle and let him float back. Or pull him in like you are fishing.
And drag him along the trail back home.
But he might get a little scratched and lose his visor along the way.
And on the way back, your mom might lose the Lego dog she was carrying in her pocket. You're so nice, you say it's ok.
But if she takes the dogs on another walk later and retraces her steps, she might find the lost Lego dog and surprise you.
And that is how you can have fun two days in a row, in a stream, if your Dad buys a new Lego set for you.