That turnover - which led to a touchdown drive for the top-ranked Buckeyes in a 38-0 victory - came 10 months after the low point for Conley at Ohio State.
He made his first start for injured Eli Apple at Michigan State on Nov. 8, and Spartans quarterback Connor Cook picked on the inexperienced Conley during their first series, connecting with Keith Mumphery for a combined 59 yards, including a 15-yard touchdown.
Apple was rushed into the game for the next Michigan State possession, and Conley rarely played the remainder of the season.
''I felt down in the dumps,'' Conley said. ''I just kept thinking about it over and over again, and that just led to more bad plays. That Michigan State game, honestly, it took my confidence away.''
But the departure of senior Doran Grant left an opening this season, and Conley used a strong spring camp to earn a starting spot opposite Apple for the Buckeyes (2-0).
''He's probably from last year to right now the most improved player on this defense,'' Ohio State co-defensive coordinator Chris Ash said of Conley. ''We knew he had a chance to be really good, but the first two games, he's proved he's going to have a chance to be a star here, and I'm really excited about what he's done.''
The Ohio State defense gets less attention than an offense that has two returning Heisman Trophy finalists (Braxton Miller, 2012 and J.T. Barrett, 2014) and 2015 Heisman hopefuls Ezekiel Elliott and Cardale Jones.
But it was the defense that shined against Hawaii, even getting a touchdown off a Bell fumble recovery and return.
The secondary limited Hawaii to 85 yards passing, the first time the Rainbow Warriors passed for fewer than 100 yards since Oct. 31, 1998.
A stiffer test is expected Saturday in Ohio Stadium against Northern Illinois.
The Huskies (2-0) are seventh in the NCAA in scoring average (47.5) and ninth in passing yards (374 1/2 per game). They are led by quarterback Drew Hare, who has thrown for six TDs with no interceptions.
Unlike that frosty November night in East Lansing, Conley said he is better prepared for the challenge. He credits cornerbacks coach Kerry Coombs for drilling into him a simple mantra: ''You're here for a reason.''
''My confidence level is the biggest factor,'' Conley said. ''Last year I was a thinker. I thought a lot about making mistakes and worrying about `What if this? What if that?' Now I just play to my ability and I know that my coaches and my teammates are confident in me.''