The "Bohemian Rhapsody" hitmakers' frontman passed away in 1991 at age 45 due to complications from AIDS and May still really misses him.
"We were completely blown out of the water," Brian told The Guardian of the band's reaction to losing their beloved lead singer.
"We just sat there in disbelief. And we didn't get over it for a very long time - I'm not even sure we're over it now - but there was a two-year period where we were grieving and behaving irrationally, almost denying the existence of Queen."
"But you do get over it to a point. And now I realise that Queen is in me and I am in Queen, and that can't change. And we got to the point where it now seems like Freddie is with us. It doesn't seem like he left anymore, because he's in everything we do. I can never have a single day without thinking about Freddie."
"I was completely convinced it was over. I remember driving past all these arenas that we used to play and thinking: 'That's gone. I'll never do that again.' I felt like I was just a very small person again. I was making my music, but I thought Queen was over and dead and gone for ever."
Queen are due to headline 10 nights at London's 02 Arena with frontman Lambert, beginning 5 June (22).