Started getting into the settlement building stuff, and just as I did, I wasn't allowed to build anymore.
Only to be disappointed to read I don't gain more XP from playing on Survival. I started having some fun despite that though. I was disappointed right as I exited the Vault because there was no 'Do you want to enable Hardcore Mode?' checkbox. Not only did it not do that, it turned it down a notch.
I was expecting Fallout 4 to turn it up a notch.
Thought New Vegas' hardcore system was very interesting and fun (having to eat, drink, sleep). Here's my story of why I had to seek out mods for Fallout 4: loved Fallout 3.