The Northern Irish-born comic, 50, also said the island of Ireland will never be united in how people feel about who they are and what they believe in.
The comedian, from Dundrum, County Down, made the comments at the Irish Government’s Shared Island initiative.
The initiative has seen the Government focus on building new cross-border and all-island relationships, backed by millions in funding.
Mr Kielty spoke about the intergenerational trauma that young people in Northern Ireland face.
“In a post-Good Friday Agreement, a big mistake that I have already made is trying to put a lid on the past and hand the new generation this shiny new page, without really talking to them or each other about the chapter before,” Mr Kielty added.
“We all pass down our opinions, our preconceptions and misconceptions. Usually without first questioning them ourselves.
“Sometimes we need to talk to people who don’t fold our own opinions back on us.”
Speaking at the event at Dublin Castle, Mr Kielty said he recently spoke to former loyalist paramilitary Jackie McDonald about their past.
The comedian was only 16 when his dad Jack Kielty was shot dead by the Ulster Freedom Fighters (UFF).
A shared island means challenging ourselves to go beyond our own comfort zones
“That wasn’t the most important part of our conversation, the most important thing was that we shared, shared a bit of our past, our pain, our hopes and our fears for the future. And it felt good,” Mr Kielty added.
“I know that sharing isn’t easy, offering up something that you would rather hang on to.
“A shared island means challenging ourselves to go beyond our own comfort zones.
“What we are prepared to give up to make things better for others, and ourselves.
“In this year of centenaries, it’s easy to honour the ghosts of the past, it’s easier to sing a rebel song about a united Ireland than decide not to sing it in order to have one. Yet, we have to be honest with each other about who we are, how we feel and it’s not just trauma that gets passed down, it isn’t just a northern thing.
“Across this entire island, not talking and not engaging means that other things get passed down too – one-sided history, stereotypes and, maybe the worst of all, apathy.
“It’s easy in a post-Brexit world to sit in Dublin and say the British Government doesn’t care about north when the truth is for many people in the Republic, they aren’t particularly interested in it either.”
He added: “Say this quietly but the shared island we are talking about is is already happening today just up the road. Is it a love-in? No.
“Is it united? Definitely not.
“Too often we get fixated with being united, remaining part of the UK, becoming part of a united Ireland.
“This island is never going to be united, and that’s okay because no matter if a border takes place, and more importantly no matter how it turns out, most people living here will feel exactly the same about who they are and what they believe in.”