Following on from Sergey’s comment about stripping and reassembling kalashnikovs in high school while flirting with the girl next to him …  A little bit of research reveals the follow: according to Mikhail Kalashnikov, the nonagenarian designer of the Avtomat Kalashnikova model 1947 (AK-47), the simplicity and dependability of the design were inspired by poetry, Russian literature and … the Bible. That probably explains why it can be used and reassembled in all conditions, from desert sand-storms to Siberian winters.