I agree with previous poster, forever houses don’t really exist, as circumstances can change pretty drastically.
We have just sold our family house, what a lot of people would think of as a forever house, huge detached, 5 bed, three bathrooms, conservatory, double garage, we lived there for nearly 18 years, moved in with 2 yo and 7mth old baby, brought the biggest house, in the nicest area we could afford, and of course we knew we wouldn’t need to move if we increased the size our family.
What we didn’t imagine happening with me was being dx with Multiple Sclerosis, which made owning such a big house, problematic especially as with shielding I had to let my lovely cleaner/friend go, impossible to cope with, stairs etc.
We have now downsized to a 3 double bed, 2 bath bungalow, much more manageable, ramp up to the front door, much more future proof, but I still don’t think we will be here forever, we shall probably downsize again, when our boys leave home.
I will never regret buying our previous family home, it was wonderful for my children to grow up in, and we sold it for over double what we originally paid for it.