home from home

I called at a neighbour’s flat in the same apartment building where I live to ask for advice as I couldn’t find a key to one of the laundry rooms. He took my hand in a grandfatherly manner (he is a father and grandfather) and said ‘ no problem I’ll show you where the key is kept’. As we walked down one flight of steps he pulled me closer to him in a strong grip with both hands despite me pulling away from him.
Until today I had greeted him from a distance in a friendly, neighbourly manner, but why does being friendly seem to equal (for many men) being given permission to touch or grope women? I am already wondering how to get down the stairs and past his flat without him knowing that I’m going into the laundry room and cellars in case he thinks he can try to grope me again.
I am furious and agitated at being treated in this way in my home surroundings.