and then I go and spoil it all by saying something stupid.... 'that's looks a nice innocuous plant, I think I shall plant some of those.

You know when something feels like a good idea at the time, you think that this plant is really quite pretty and you would like some?  Then it starts to self seed a bit and you are happy and encourage it.  Lets face it, self-seeders often place themselves in far better combinations than I could design.  But them, suddenly you have swathes of it, it is smothering everything around it and turning up all over the garden.  This is the moment when you realise that whilst you still want it, probably still want lots of it, you are going to have to impose some control.  Does this sound familiar or do you have more sense than me? (don't answer that, I know you do, you must do).
It's not like I have only done this once, no, I am a repeat offender.  I can have at any one time a considerable amount of:

Nigella -  I pull it up by the handful as there is plenty more where that came from, it is lovely and I would not be without it, but it needs editing

Ox eye daisy - same as above

Allium 'hair' - same as above

Teasels - these I edit more carefully, I remove totally from some areas and allow to roam free in others,

Purple orache - every seed germinates, every single seed

Woad, gorgeous plant woad, seeds around like the devil though,

Annual poppies, welsh or somniferum in particular, I remove many and yet always have enough,
and Claytonia sibirica, well I think that's what it is anyway.  In truth I didn't plant this one, it was planted by someone else.  It is quite pretty but very prolific.  It self seeds everywhere and whilst easy to spot and remove there is something about it that I don't like.  There's something about it that's a bit weird, it has a smell I don't like and I don't like the very watery stems.  I'm told its a sort of salad, this might explain the dislike, I don't do salad. 
So I dig it up

It creates space.
Good job I've learned my lesson and not sown any ransoms lately.........