"Going into Boston that day, we felt like we had a pretty darn good chance of winning," Ryan told ABC News in an interview broadcast Tuesday. "So as you can imagine, it was a bit of a shock when we didn't win, but that's just the way these things go."
Ryan said President Barack Obama deserves to be congratulated for having "a fantastic ground game."
"He won fair and square," Ryan said of Obama. "He got more votes, and that's the way our system works, and so he ought to be congratulated for that."
Had he been at the top of the ticket, Ryan said, he would have run exactly the kind of campaign that Romney oversaw. Ryan said he and Romney "felt very good about the race we ran."
Ryan, who was re-elected to an eighth term in the House, returned to the Capitol on Tuesday to resume his duties as House Budget Committee chairman.
"There's an upside to losing," Ryan said, "which is a reconnection with my family." He said he had already attended basketball and volleyball games in which his children—he has two sons and a daughter—were playing and looked forward to taking his daughter deer hunting.
"Bad news: Dad lost. The good news: They get to stay at the same school," he said. "That was the upside of all this. The downside is we didn't win the election that we really wanted to win."