Equally so, they may have forgotten just how good the Leeds indie band were in their pomp.
He is reunited with them now, however, and, if this energetic, vibrant performance at Dalby Forest is anything to go by, sounding as good as ever.
Kaiser Chiefs are back with a new album released in October and a new single – Parachute – already out.
It has been met with mixed reviews given its leaning to a more dance-pop vibe; on Sunday night, though, it felt like it was already one of the band’s countless classics given the way the crowd - unswayed by the rain that had driven down on the Forest Commission’s latest gig - embraced it so enthusiastically.
That Wilson opened with We Stay Together, another song from the band’s new album, showed the confidence he holds in their latest material and it didn’t back-fire.
Attired in a luminous pink leather jacket, he instantly looked more at ease than on any TV programme, promised to “entertain” and didn’t fall short, launching into Everyday I Love You Less and Less with his usual gusto followed by Ruffians on Parade and Everything Is Average Nowadays.
After Little Shocks and the aforementioned Parachute came favourites Never Miss A Beat and Modern Way but, of course, Ruby and I Predict A Riot are true highlights, still as anthemic now as they were in the mid-noughties.
In between, Wilson introduces his band-mates before musing “the things I’ve done for them; three years on The Voice….you get less for GBH.”
You sense he is only half jesting while the lyrics in Angry Mob suddenly sound particularly apt considering the events of the week leading up to Sunday’s show.
And on that note, what a great way to forget about all the uncertainty and concerns, for many, brought about by Brexit; 90 minutes of splendid escapism and a welcome return from the Leeds rockers.