There are so many parameters to be considered before concluding on whether or not one is great or otherwise. Greatness is also related to differing situations or circumstances. One might be great in this or that aspect of life. It may be in academics, business, professions like Law, Architecture, Athletics, Politics or Medicine. The level of success and the extent to which the individual had created joy, peace and many more for the society, usually determine how great the person is. Sir Winston Churchill was full of regrets that he had not the luxury of attending Oxford or Cambridge, the two premier Universities in Britain but yet he became a great statesman and wartime resilient Prime Minister of Britain. His greatness was not in contest with the like of Jeremy Bentham who was a great political philosopher.
Adolph Hitler was known for his being pathologically wicked in the way he perceived others as against his Deutschland and especially his total abhorrence of the Jews with the attendant pogrom and disruption of peace in the world to say the least.

Focusing on Methuselah, we read from the bible account that he lived longest of all known people of the world for a total of 965 years. Is that not great? There was no record of sin. He did not drink to stupor to a stage of having to sleep naked that could have led to sodomy. He was not known to have cursed his children or any other person. He was not known to have sinned against God. One can surmise that he was a good man but recorded no spectacular feat like his father Enoch. “And Enoch walked with God; and he was not, for God took him” Genesis 5: 24. Greatness in any field that will benefit humanity should be the prayer point for all believers in order to leave their footprints on the sand of time.