He loves stickers since. The first few months we gave him those loose 1 piece stickers, and he was just anyhow pasting the stickers onto anywhere. Table, sofa, books, shelves, human, clothes, etc, and he likes to take it off after sticking too. Not long ago, we introduced to him stickers book. Intially, he still pasted the stickers randomly onto the book. No long after that, we realised he actually know exactly where to paste the stickers, and he pasted it nicely and precisely onto the slot. If the sticker wasn't placed nicely, he would took it off and redo until he is satisfied with it.
This is the most recent "masterpiece", just completed an hour ago. He was able to pick up those same/similar animals from the sticker page (arranged randomly) and pasted them nicely and orderly onto a blank page. He did this without any help from us (as we were busy running chores, didn't notice what he was doing :-P) This is how it looks like:
I hope he has had fun. And this is what I would call "learning through play" :-)