I came across this analogy recently and found it very appropriate https://www.quora.com/Why-are-software-development-task-estimations-regularly-off-by-a-factor-

I came across this analogy recently and found it very appropriate https://www.quora.com/Why-are-software-development-task-estimations-regularly-off-by-a-factor-of-2-3/answer/Michael-Wolfe?ch=10&share=a82e31c9 https://www.quora.com/Why-are-software-development-task-esti.... It is a fictional story of two friends who want to walk from San Francisco to LA down the coast in 10 days and how all their assumptions are shown wrong when they start doing it.