Preparing for the April 11 start of the Masters at Augusta National, the 29-year-old Spaniard talked about the consequences of his decision last December to leave the PGA Tour and watching on television as others won titles he took in 2023.
"For everybody who said this would be easy, some things have been, but not being able to defend some titles that mean a lot to me hasn't," Rahm said.
Rahm won last year's PGA Tournament of Champions in Hawaii, the American Express at Palm Springs and the Genesis Invitational at Riviera, before capturing the green jacket.
But he is banned from PGA Tour events after joining LIV, where he ranks second on the season points list after top-eight finishes in his first four events.
"I love Palm Springs. I've been able to win twice there. Riviera is about as charismatic of a golf course as we have. Not being there was difficult," Rahm said.
"I still watch golf because I love watching it. But it's hard. It was hard not to be at the Phoenix Open at the end of February and it was hard not to be at Hawaii."
Rahm is looking forward to returning to Augusta National, where he will face a field of the world's best from both rival tours.
"So far, it has been great. Been playing good golf," Rahm said. "But I'm definitely looking forward to joining with the rest of the best golfers in the world and teeing it up at the Masters with them."
Rahm's only repeat crown came at the 2019 Spanish Open.
"This could be my second ever title defense. That would be quite incredible," he said.
As pained as he was to miss his chances earlier this season, Rahm said he will let those memories fade.
"I don't know if I would have and will be thinking about those tournaments I haven't defended.
"It's done. It's past. It's a decision I made and I'm comfortable with it. But I'm hoping I can come back and hopefully I can actually defend this one. That would be a dream come true."
Only Jack Nicklaus, Tiger Woods and Nick Faldo have won back-to-back Masters titles.
'Room for all of us'
Rahm enjoyed watching top-ranked Scottie Scheffler win his second Players Championship in a row on Sunday, with some longing of his own for another showdown at TPC Sawgrass.
"I hope I get to tee it up at The Players again," Rahm said. "It would definitely be a weird feeling if I never get to do it again."
Merger talks between the PGA Tour and the Saudi Arabia Public Investment Fund, LIV's backers, continued Monday with several PGA players involved, including Woods.
Rahm hopes for a reunification so the world's best golfers can meet more often.
"I just want to be able to see the best in the world compete against the best in the world, whatever that looks like," he said. "I think there's room for all of us."
Rahm does not expect difficult confrontations between PGA and LIV players.
"So far I haven't had any bad experiences," Rahm said. "I've seen other PGA Tour pros and I haven't really seen anything bad.
"I'm assuming there will be quite a few that are not happy and maybe our dynamics has changed, but from my side, nothing changes. I still respect everybody on both sides and respect the game of golf above all."
Rahm, who plans to visit Augusta National next week for two practice rounds, said he thinks LIV's team concept has a place in golf's future.
"I believe there's room for team golf and individual golf," Rahm said. "If there's some type of peace achieved, I think it can actually push the game forward."
