Very random

Yesterday, I found this Grey Dagger moth Acronicta psi  just randomly sitting on my dining room wall, which was very odd as this common moth flies between June and August in the UK and certainly NOT in January!!! 
I can only think this is the Grey Dagger larva that went missing in my dining room, which would have made perfect sense if that had been last August, but it was in August 2013! 17 months ago!!!!!!
Don't get me wrong I am more than happy to have a Grey Dagger moth in residence, but what to do with him I have no idea! I guess he will just have to live his days out in my huge flight cage :-(
Life is really odd sometimes :-((