It doesn't hurt to know what is out there but you don't need it all, that is for sure.
I try to stay current on what I could get even if I don't, just because I think it is interesting.
For example, I have cheaper Tamron versions of popular FF lens ranges (28-75, 70-200) because they were good enough for my needs. I do some pro work and there wasn't anything the more expensive lenses offered that was keeping me from producing the required results so I saved some cash and got the cheaper stuff.
The Pentax versions look great and one day I might need them for a job that requires WR but so far I haven't so I'm enjoying what I could afford at the time I needed it.
But it's ok to dream...