This doesn't happen to me too much on Wattpad, but it's happened to me a couple of times on FanFiction.

And that is finding a really good, amazing story, and once you've read all the published chapters, you notice that it hasn't been updated in two years.

This has happened to me twice on FanFiction.  The first one was a cool story about a women's prison, where the prisoners are all Divas, and AJ is accused of murder (I think) and gets put in prison.  And then all the guards and such are Superstars, and it ended up being a PunkLee story, and I don't normally read stories about them, but it was so good that I had to keep reading.  It had about 60 chapters when I read it, and when I got to the end, I realized it hadn't been updated in at least a year. >.< It was the first AU story I got really into, and it just hasn't been updated.

The second one was also an AU story, but everyone was some sort of creature, like a werewolf, siren, or vampire.  The chapters were really long, and it had about 40 chapters (because she would split some chapters in two) and it was really good!  She would update occasionally (like, every few months), but I think she stopped writing it (that, or she's editing all the chapters, I can't remember).

Now, I check to make sure the story's been updated recently.  If it's been more than a few months, I try to avoid it.  If it's been years, I don't even read the description; I get away from that story before I get attached to it.

This rant was pretty pointless, but I needed to get it out of my system. xD