Well over half of those at retirement age reported to have never experienced deja vu, while only one-fifth of those in their late teens and early twenties said they never had. Subconsciously, these elderly denizens are probing the experiences they've had in the recent past and projecting them back across their hazier memories of earlier times. There is a sort of familiarity bias of shorter-term memory present in the responses of these older folks, who had not recently experienced nearly as much deja vu as they had when they were younger (as deja vu is apparently a side effect of a better functioning memory system).
While it's something worth being aware of, I'm not trying to be critical of unintentional inaccuracies of those whose lives are past noon. It's part of the human condition. A lot of great art is devoted to trying to rekindle in us a neotenous frame of mind that is probably impossible for most of us to ever return to once we've left it. While we might get close in our most pensive moments, it's only passively so, as though we're watching video footage of earlier times in our lives play out. And most of the time it's out of mind, out of sight altogether. C'est la vie.