. ♪ >> reporter: but accordi ining isaacson there was another steve the public never saw. talk about his ability to devastate people with a stare or with a tantrum. you write he could stun an unsuspecting victim with an emotional actual snap perfectly aimed. >> a lot of tech geeks, i do cover them all the time, they're kind of disconnected emotionally. they don't emotionally engage. they have trouble making eye contact. steve was at the other extreme. he knew emotionally every single thing about you. when he was upset with somebody's work, he wouldn't just sort of rant, he would rant in a way that would get right to the core of somebody's emotional weaknesses or vulnerabilities. >> reporter: isaacson cries how many were the people he loved the most. the friend who helped build apple then was frozen out of well-deserved options and a girlfriend who wrote neglect is a form of abuse and the daughter he refused to acknowledge even after a court-ordered dna test proved he was her father. >> he said it's one of the th g things he regrets in his life. he didn't handle it well whe