[GTALUG] Ubuntu (or debian): apt-get auto-remove?

[D. Hugh Redelmeier]

After my update from Ubuntu 12.04 to 14.04, apt-get tells me that there 
are a lot of packages that apt-get auto-remove could remove.

Is that safe?  What is the underlying idea?

I think that it removes things that were added due to dependencies where 
those dependencies no longer exist.  In the back of my mind, I worry that 
sometimes dependencies might be things that I wanted independently of why 
they were installed, but I'm not sure of that.

Do people fine apt-get auto-remove works great or do you find that it 
throws a few babies out with the bathwater?