When I was a child my parents gave me a toy that was basically DIY optics projects. It included a telescope, binoculars, and a 35mm camera with telephoto lens. It was all plastic that snapped together. Unfortunately, I never successfully assembled the camera - but it did help me learn.
* "So much time and so little to do. Wait a minute. Strike that. Reverse it. Thank you." (the original Willy Wonka: Gene Wilder, 1971)
* My favorite cameras: Leica SL, Leica M7, Russian FKD 18x24, Bronica SQ-B and RF645, Rolleiflex T2, Nikon F4s, Agfa Clack and my pinhole cameras