volitional + とは (never thought I would)

Volitional form + とは, typically followed by a verb of thought/expectation in negative form (思わなかった, 夢にも思わなかった). Highlights the very fact of doing/being something as surprising — 'never thought I'd ~.' Often paired with まさか for emphatic incredulity: まさか会おうとは夢にも思わなかった ('I never dreamed I'd run into him').