We in the west seem to have a bit of an obsession with significant dates - birthdays and wedding anniversaries being the most obvious, but any number of others, often those of personal significance that no-one else on the planet will recall. I'm not sure there is a whole lot of rhyme or reason to what is significant for a given individual... things that seem to me inconsequential are to others hugely significant and vice versa. And some of it is about personality quirks - for some people dates, times and places just 'stick' in the mind or a triggered by such diverse means as hearing a particular piece of music, smelling a certain scent, or even eating a specific food.
My own canon of significant dates includes some happy/positive occasions, such as my baptism, my sense of call and my ordination, and some not so lovely... my "cancerversary", the dates I started chemo and had my initial surgery are graven on my memory (though interestingly not the date I started rads but the day I finished them!). Some are actual calendar dates, others are linked to liturgical dates (so, for example, I recall my Dad's death on the Wednesday after Easter rather than the actual date; my first sense of call on the second Sunday in Advent)
Yesterday was a milestone day - a marker that made official what already was (and which coincided neatly with the anniversary of going into hospital for my initial surgery, five years ago!)...
The officical assertion that I am now five years NED is a significant milestone in some ways, hence why I felt so unexpectedly happy about it, yet it is at the same totally artificial: due to an admin mix up my appointment had been delayed by a week, so I could have reached it a week earlier or a fortnight later, just dependent on when the appointment landed. The marker doesn't actually change anything, at least not in terms of hard facts. But it does change something inner, more nebulous, less precise.
The friend who five and half years ago said, "nothing has changed except now you know" may rue those words, given how deeply rooted they are in my psyche, yet they remain as true and as untrue as they were then. Being told you have cancer does not change anything physically, but it totally changes your world, it is, in my opinion, an irreversible paradigm shift. Being told you are still NED not only doesn't change anything, it is inherently imprecise, unproven, yet it makes a huge difference inside. Reaching five years is a significant milestone, it is a figure that carries an air of mystique, and that is sometimes, unhelpfully, equated with cure. This isn't a pardigm shift, there remains a level of uncertainty; a real, if diminished and diminishing, risk that something as yet undetected and undetectable may yet arise. As others have said, the day you know you are cured of breast cancer is the day that you died at a ripe old age and something else appears on your death certificate!!
I think what I have learned, at a generic level, is to value my own milestones and markers, not to be embarrassed that for me 23rd August and 2nd/3rd February are hugely important dates, right up there with 5th October, 6th December and the Second Sunday in Advent, even if for very different reasons.
Most of these milestones and markers are not paradigm shifts, which is a good thing! Most of them will become less significant with time, will pass unobserved, if not unremembered, and that is a healthy thing too, I think.
Five years of NED means the risk of recurrence has significantly diminished, that the risk of a new primary is falling closer to the societal average (and will reach that at around ten years from diagnosis). Nothing dramatic has changed or will change, but as a personal marker, a date I genuinely feared I'd never see, it has personal significance - which I guess is good enough!