It didn't take long to get the answer, and if you were one of the millions of Federer fans around the world, that answer wasn't very appetizing.
Federer confronted a similarly towering, big-serving rival in the semifinals in Milos Raonic, and this time exited in five sets to quash the 34-year-old's hopes -- not to mention those of his faithful, adoring supporters -- of becoming the first man to claim eight Wimbledon titles.
Whereas 2014 U.S. Open champion Cilic will feel he should have ousted Federer, the latter leaves SW19 thinking he should have prevailed against the sixth-seeded Raonic.
"This one clearly hurts because I felt I could have had it," he told reporters. "So close. It was really so, so close.
"There were opportunities there."
As is sometimes the case when Federer loses, he went from the court to the interview room almost immediately, not wanting to linger, even if he was at his second home.
"Yeah, so opportunities were all around the fourth set. I think I pushed him on a few service games to get the break. But somehow I couldn't get it done."
Instead Raonic triumphed 6-3 6-7 (3-7) 4-6 7-5 6-3 to become the second Canadian to reach a grand slam singles final after Eugenie Bouchard did it here at Wimbledon two years ago.
Coming up short in his previous two grand slam semifinals -- once to Federer at SW19 in 2014 and to Andy Murray at the Australian Open this year as injury surfaced -- his time has arrived at the age of 25.
"Obviously what happened here two years ago, I was very disappointed with," Raonic told reporters. "Today I sort of persevered. I was sort of plugging away. I was struggling through many parts of the match. He gave me a little opening towards the end of the fourth. I made the most of it.
"The attitude kept me in the match. I think that's what made the biggest difference. I was quite vocal, but I was always positive. I was always looking for a solution."
The 2013 champion brushed aside 2010 finalist Tomas Berdych 6-3 6-3 6-3 in Friday's second semi.
Murray, unlike Raonic, is a veteran of grand slam finals but is desperate to try to better an unflattering 2-8 mark.
Those assembled on Centre Court witnessed history Friday: It was the first time Federer lost a Wimbledon semifinal in 11 attempts. It was probably the first time, too, that Federer called the trainer for two different issues.
At the end of the fourth set his right thigh needed attention, and then at 1-2 in the fifth he slipped -- a further anomaly -- almost rolling his left ankle and appearing to tweak his left knee.
Both incidents may have played a considerable part in the outcome.
Was the thigh bothering Federer in the last game of the fourth set, when he inexplicably dropped serve from 40-0, hitting consecutive double faults from 40-15? Federer, who also double faulted on break point in the first set, didn't produce one double fault against Cilic.
When he returned to the court in the fourth game of the fifth following the slip, the first point he faced was a break chance for Raonic. Although he saved it, Federer was broken later in the game following a riveting exchange near the net that culminated with Raonic's forehand passing shot.
Down 3-1, Federer never recovered and Raonic registered a second straight win over the 17-time grand slam winner.
"I had missed my chances by then already, enough," he said. "Maybe I could have stuck around better if I would have saved break points. Very disappointing half an hour there for me, getting broken at 6‑5, getting broken again at 2‑1, having the slip.
"Who knows what happens there. But it was a very disappointing end to the match for me."
Indeed. Federer led on Raonic's booming serve four straight times in the fourth, including 15-40 at 2-2 and 0-30 at 5-5, unable to gain what would have been the terminal break. Overall, he went 1-for-9 on break points.
Despite Raonic mixing things up by serving to Federer's body, his overall serving numbers -- 23 aces and 11 double faults -- suggest this wasn't his greatest delivery day.
Carlos Moya, one of Raonic's grand slam-winning coaches -- three-time Wimbledon champion John McEnroe, who came on board last month, is the other -- pointed to the conclusion of the fourth as the turning point.
"Roger, I would say he kind of opened the door for Milos to have the chance to come back -- and at this stage of the tournament you pay for that," Moya told a group of reporters. "That's what I think because Milos was struggling a little bit on Roger's serve and as soon as he had the chance there and he converted, in the fifth set he had a slight advantage (after) coming from behind and probably that game was key."
Entering Wimbledon, Federer perhaps would have been happy enough to make the semifinals given he skipped the French Open and other chunks of the campaign due to back and knee injuries.
But his good fortune against Cilic and the absence of nemesis Novak Djokovic in the second week -- he was upset by Sam Querrey in the third round
-- might have got Federer thinking about landing an 18th major and first since beating Murray in the Wimbledon final four years ago. From Murray's perspective, he'll be relieved that Djokovic isn't standing across the net Sunday.
Federer must now focus on new targets -- or pre-existing ones that had nothing to do with Wimbledon.
"It's not my only reason why I play tennis, just to be clear, otherwise I'll go in a freeze box now and come out before Wimbledon next year," he said. "I know Wimbledon is important, but it's not everything, everything. There are a lot of things that I'd like to achieve besides winning Wimbledon."
One, presumably, is winning a first Olympic singles gold medal in Rio next month, having settled for silver against Murray at London 2012.
This year at Wimbledon, though, Murray or Raonic will be doing the winning on the day it matters most.