Speaking to the Press Association, Boothroyd said: "What you deserve and what you get tend to be different.
"As the song goes on the terraces we were 1-0 up and we messed it up - or words to that effect.
"We didn't play particularly well but got ahead and then we gave away a soft goal. It could have been easily avoided.
"In the second half I felt we were the better team but Forest are a good side. They finished third last year and you can see why. They are battle-hardened while we are a work in progress.
"We have to deal with that. We got into a good position and didn't see it out.
"After two months of the season we should take something from a game where we take the lead but it's a few more grey hairs for me and something else to sort out. "It's a very tight league."