It is hugely depressing as you are doing nothing productive yet you can never plan to have the next x months available to do a project on your own.
What most bugged me down was the BS busywork, which kept coming as the office was small enough for people to know I was on the ever delayed project. If I could do it again I would just go skiing fulltime and tell them to fire me or staff me, but I was an extremely ambitious 22 year old and stuck in a role that is generally considered at least a 2 year commitment.
I finally quit 9 months in, with my "mentoring partner" reassuring me the project really would start in 2 weeks. Literally 20 minutes before he had said that there had been an email from HR that it was delayed again. The idiot just didn't care. When I asked him to explain how the company had not wasted my time over the past 9 months and why I should trust their promises going forward, he went all office politics on me saying that this was an evaluation only I could make. That was the last insult to my intelligence that I tolerated from that company.
I'm still extremely angry over it, as I was doing everything right. I had a ton of savings in index funds already and had it all planned out to work hard and retire extremely early. When I quit I was so depressed that I did not even fight for the extra 3 months of severance, which I'd have gotten if I had let them fire me officially. I also didn't stay another 3 months so I could take unemployment benefits. The bit of money in the company pension plan was also lost as it had a 12 month vesting schedule. Basically, here was a guy who had been top of class all his life and with a savvy personal finance plan, so broken from 9 months of soul destroying nothingness that he quit without any backup what so ever.
It took me 3 years to get over it. Literally, for 2 years and 4 months I sat at home reading stuff. It was only when I was almost 26 and completely broke that I applied for a startup incubator, got in, and got back on track somewhat. Now that that company failed, the rational thing would be to apply for a rails developer job. I found some rails shops that I like, but I just can't get myself to press "send" on the application email. I don't think I will ever trust anyone enough to work for them fulltime.
If you're still reading this at this point, take away one lesson: Do not hire ambitious, talented people if you don't know FOR SURE you can give them meaningful work. Better to remain friends with a talented person who is now working for somebody else than to employ him and turn him into an enemy for life. (Because yes, I will have my revenge and it will be fucking brutal. Legal, but oh so brutal.)