How come the past of ‘go’ is ‘went?’

Thanks to colleague Aurora Humarán for this enlightening article.

Very long ago, one of our correspondents asked me how irregular forms like good—better and go—went originated.  Not only was he aware of the linguistic side of the problem but he also knew the technical term for this phenomenon, namely “suppletion.” One cannot say the simplest sentence in English without running into suppletive forms. Consider the conjugation of the verb to be: am, is, are. Why is the list so diverse? And why is it mad—madder and rude—ruder, but bad—worse and good—better? Having received the question, I realized that, although I can produce an inventory of suppletive forms in a dozen languages and know the etymology of some of them, I am unable to give a general reason for their existence. 

How come the past of ‘go’ is ‘went?’