Most people are involved in their own issues 99% of the time. Obviously I don't know the exact scenario and maybe they are ignoring you. Most of the time they just have something going on in their head and aren't thinking about ignoring people at all. It takes courage and practice but you could approach them casually and see what their reaction is. What's the worst thing that could happen? They ignore you... Then you know More often I think you'll see what I'm talking about and the you can be annoyed with how ditsy everyone is