Bruce has done 20 years in the dug-out since starting as player-manager for the Blades back in 1998, but “horror stories" behind the scenes initially put him off.
Ahead of tonight's return to Bramall Lane, the Geordie recalled: “Now I look back at Sheffield United and think they gave me this chance.
"How fortunate have I been? I've been at the coal face of football for nearly 40 years and had only 15 months' break in that time. It's given me a wonderful life."
Bruce also spoke of losing Dean Saunders to Benfica when in charge at Bramall Lane.
He said, “Dean said, 'Has no-one told you? I've signed for Benfica 20 minutes ago'. I knew nothing about it. That gives you an idea of what it was like. I didn't know who to call to rant and rave.
“I thought, 'Is this (management) really what I want to do? Do I want to put myself in that situation?'."