Actually, you could comfortably reach quite a lot of points in the universe in your lifetime, provided you'd have a free constant thrust engine. This one not, because it's out of our light cone.

Sure, "quite a lot" in an absolute sense, but the fraction of the visible universe that's still reachable is quite small. IIRC, something like 4%. Don't quote me on that.

I fear you have lived up to your handle and missed the point? Your last sentence is exactly what he was pointing out.