I love Borage. The bees love Borage. I love bees working in the garden. Win-win, lol.
I've got some self-seeding in places, although they made a late start this year - not sure why. In one new garden made mainly with last years compost I watched one plant develop with great curiosity (you never know what will spring from a compost heap) and at first thought it was something in the curcubit family but then it just kept growing, with no sign of putting out tendrils or anything remotely curcubit-like ... anyhow I waited some more .. and waited some more ... this thing was becoming rather large. Then it began to develop flowers so I thought "cool, I'll finally be able to identify it". Turns out it is a huge Borage plant!
Bonus! :D
What a GREAT story! That is the sort of thing I would do too. It's growing so let it be till you see what it is, lol.