It is not that wierd really, it happens more than you think.
I have a similar situation, but in reverse!!
I have been looking for information for a friend of mine on his uncle who left here in Northern Ireland for Canada sometime prior to WW2.
Similarly, no one in the family spoke much about him, and it is only recently that the subject has come to light again.
I have recently sent a letter to someone who I think could be his daughter, and await a reply (if any is forthcoming).
Do not give up yet you are not at the
stage yet.
The marriage certificate
might give his father's details, but don't bank on it. It quite often happened that those details were not added if the person was not a UK national.