I had a dream of my neighbor who had ped away about a month ago what does it mean?

In this dream I see him walking in his front yard and I say hi to him and he says hi back I know he ped away but in the dream I'm the only one who can see him. When I try to show my sister that he is there she can't see him so I ask him to give my sister a flower and a flower pedal and he does. My neighbor was like a grandfather too me great man! But if you can help me out in figuring what this might mean I would appreciate it.