The article presents a reflective examination of what has worked in computer system research, as opined by Butler Lampson in 1999 and reevaluated in the modern context. Noteworthy is the persistence of previous ‘Yes’ categories and the evolution seen within ‘Maybe’ and ‘No’ classifications, with particular attention on developments in parallelism, RISC, garbage collection, and capabilities. The conclusion underscores the volatile nature of predicting future technological successes and recognizes the impact of computer systems research over nearly two decades.