A cornflower, or not a cornflower...

that is the question. Can anyone advise?

It's beautiful. I noticed these growing in our neighbours' gardens and was thinking how pretty they were, when hey presto, I realised I had one in the front border. It has self seeded, and from what I have been able to find out online, it seems to be a cornflower, but I'm not sure. Perhaps it is a wildflower rather than a garden variety?