If you give an adult LEGO enthusiast a brick…
When you give him the container, he’ll probably ask you to help find all the bricks in his inventory of the same shape.
When he’s finished finding all the pieces of the same shape, he’ll ask you to help sort out all the like colors of that same shape.
Then he will want to build something out of his newly sorted pieces, but he’ll need to get out his other pieces out too.
When he pulls out his other pieces and gets to work, he’ll notice he needs to make a BrickLink order for more of those pieces to finish his new creation.
When he makes that BrickLink order, he might throw in a few more pieces, just because they’re cheap and he doesn’t have them!
When he finishes his new creation, you’ll have to get the camera, white backdrop, and lighting for him to take a picture of it.
When you upload the pictures, he’ll get so excited about LEGO creations that he’ll want to look at everyone’s latest activity.
Then he’ll want to go see the creations in person at the upcoming brick convention, which means he’ll need to bring something to display or to enter a competition.
He’ll decide what he’s going to build and then start to think about what pieces he’ll need to make it. Chances are, he’ll need another piece he doesn’t have or more pieces of the ones he does have.
And chances are if he asks for another brick, he’s going to want another storage container to keep it in.