Naw, you're not crazy
Your normal !!! I would have been worried and alarmed too! We expect that our dogs will bark when we need to notice something they think is out of the ordinary. Dogs alert us to strangers, dangers,etc. That was/is their originally main job I think
Seems though, if it was your dad, he would be a friendly spirit.
I got my dog after my dad passed away too, I am sorry for your loss