It would seem to me that there are two ways that others can make you feel invisible (and vice-versa):
1) By plainly ignoring you. You feel ignored, alone, invisible. This one is quiet obvious.
2) By adapting themselves too much to you. And this is what is a new/strange thought for me.
The logic is the following: When the people around you entirely mold themselves around your wishes and desires, they virtually create no resistance in the decisions you make and your path in life (and thus also have no influence on it). It is as if there was nobody. No solid human being. Just thin air enveloping you... No matter how hard you wave your arms you will feel at most a slight breeze.
Once more you will feel alone, and invisible... How ironic (and funny).