As a ghost I would ask myself why when I want to hit a wall I fall through it but why I’m already not falling through the ground. (ever experienced this bug where you fall into ground?)
But actually I will be floating and not particularly stepping anywhere on the ground. So this tells me I can go through the ground too (but can’t see anything because of no empty space in front of my eyes).
But the fact is, whoever said as a ghost I will be having the same human shape as I had before I turned into a ghost? (So probably no eyes).
What if someone lost both their hands before they died? the poor ghost would have no hands for the rest of eternity? (So definitely I’d be taking another form after death).
I imagine I’ll be some sort of energy-ish. (what’s going on?)
After all, whatever I am after death, I’d probably not be around this physical realm. (guess what, countless of people have died since the first humans on this planet till now. If they all wished to stay around this world, travel, and bother people it’d be so crowded and not a fun place for a ghost to stay).
All in all, if I was allowed to move around freely without any invisible walls my fantasy is to move straight forward into the space until I actually hit that the end of the world wall.
(Better get to sleep before I actually become one)