ЖИЛ-БЫЛ folkVPsubj: humanpast onlyalways precedes subj) the stock phrase used at the beginning of folk tales: once upon a time (there was (were, lived)).
«Жил-был, здравствовал, изучал математику и прочие точные науки и никогда не думал, что стану таким „шовинистом"» (Шолохов 2). "Once upon a time I was a student of mathematics and other exact sciences. Little did I think I should live to become such a 'jingoist'" (2a).