Well I know the Pink Floyd question was slightly different and anyway, the answer wasn’t all that difficult. The three pieces of furniture a guy like me needs are a bed, a desk or table and a chair. Especially as the flat came with some storage spaces already in the kitchen and the hall. On the day I got the keys I bought the above-mentioned three items and the next day they were delivered. Putting the bed together took two and a half hours; the desk took two; the chair was easiest, under an hour. The interior began taking shape.
Of course, by that time I had already been contemplating what else to do with so much space (I had never had so much before). But I’ll have lots of time to contemplate that. These things are costly and I’m sure I will only be adding an item at a time, with long intervals in between. So the question is rather: How shall we heat all these empty spaces? Because electricity apparently costs much more than I had imagined.