People make many choices in their lives. There are times when people regret their choices and fantasize about the paths not taken.
ご質問ありがとうございます。
"People make many choices in their lives."=「人々は多くの選択を人生でする。」
"There are times when people regret their choices"=「自分の選択を後悔するときがある」
"and fantasize about the paths not taken."=「選ばなかった道について幻想を抱くこともある。」
☆「自分が選ばなかった選択に夢を持ち・過大評価し」= "They dream about the choices they did not make" or "They mistakenly value the choices they did not make"
ご参考に。