Gifts which helped shape your mindset while growing up

I believe a tool/gadget/book we interact with when we are below 10, impacts and shapes our mindset for growth.

For me, it was a science projects book I got from my cousin, it had basic and advanced projects, which increased my interest in science/physics/chemistry.

Tell me about that gift (book/tool/gadget) which had an impact on you, without which you would have been a different person.