Quite a long list actually and hard to put in words.... Functional programming in general..especially its roots( halting problem, church's thesisetc...),reading about ENIAC .... small-world problem(miligram) and modelling such networks,beauty of primes and number theoretic algorithms,quantum mechanics. Several books have also influenced deeply...textbooks/sci-fi/cyberpunk...works of hofstadter,stephenson etc....