I would like the ability to decline my own events.

The use case is this: I have plans for the future, and I note them down as calendar events. Plans change; a happening I had planned for tomorrow may be cancelled or moved to a different date. However, I would still like to know that I originally had something planned for that time.
This would be useful in a number of scenarios:
* when the event needs rescheduling, but a new time has not yet been decided upon, this can serve as a reminder that the event exists, instead of just deleting it and then forgetting it.
* when trying to remember what I was up a couple of weeks ago, I can see why I had nothing going on one day, instead of just that I had nothing going on.
* it can be useful to have some idea of what my immediate future looked like in the past, to illuminate why certain decisions were made or certain dates were chosen for other unrelated events.

One "workaround" is to just delete/reschedule these events, but that does nothing to meet this use case.
An actual workaround would be to create a separate calendar to hold declined self-initiated events. This would work, but it's not a neat solution. If you want to keep track of which calendar an event came from (e.g. work calendar vs. personal calendar) you would need one extra calendar for declined events per normal calendar. This also leads to a lot more unnecessary switching calendar-visibility on and off in the settings. The events also wouldn't be styled as declined.
More importantly, that workaround feels very suboptimal when calendars already have good behaviour for declined events; there just happens to be no way to decline own events.

This doesn't on the face of it sound like a big task. Sounds more like what needs doing is removing a restrictions that you cannot decline your own events.