Adam Robinson, the Texas tech entrepreneur who died alongside his wife and two young children in a horrific private plane crash in Florida, was really big into flying private ... so much so he says it "became part of my identity."

Adam detailed his use of private jets in a recent podcast, explaining how his rich friends got him into the lifestyle.

He says he would be at dinner with his hedge fund bros when someone would ask the table if they wanted to go to Las Vegas in a few hours on a private jet ... and he would jump at the chance.

Adam says his friends used private jets as a status symbol ... and when he realized he could afford them too, he began flying all over the place ... spending thousands of dollars per month on PJs.

He says flying private "became part of my identity" ... it was almost a flex.

Adam was flying private Sunday with his family, nanny, and two friends when the jet nosedived in Florida and crashed.

They were on their way to the Bahamas to celebrate Adam's birthday.