I think there's also nuance in what "actively looking" means. Someone might decide to stop actively looking but not permanently retire and instead wait until conditions are different; maybe someone in their 20s or 30s might move back in with their parents for a bit, or maybe someone just decides that living more modestly for a year and then trying again either when more jobs are available or when they're less burnt out. Even less common things, like having to go on disability to to an injury or illness might add up to a decent number when aggregating across an entire country. I think the main point is that the single statistic alone doesn't describe "why" or "for how long", only "how many"; there's (almost literally) a world of potential reasons that aren't necessarily going to be related to any others.
