Is Selflessness possible?

Sure. Also of all attachments ones children are the strongest. So the light of wisdom is necessary to live within attachment and yet to not be of it. And the light of wisdom is quickly and clearly seen when one is in samadhi, if you can use that as a knife to cut through diversity. Sure, it's easier said than done, especially if ones aproach to Buddhism is merely philosophical. Buddhism is a living breathing religion which remains to liberate the bound mind too whatever degree it can take.