The trouble with being adopted within the family you were born into, is that if it's kept secret (as it was in my case) from the child but not the rest of the family, there is a huge burden imposed on everyone to keep that secret from that child until he or she knows.
In my mother's family this meant forever. It also meant that I was subtly kept isolated from relatives as I grew older, including my birth mother, who I grew up believing was my aunt. I was never encouraged to write to anyone, aunts, uncles, cousins. Mother was terrified, I think, someone would slip.
I had three remaining cousins, with whom I have over the years lost any contact with. Last night, out of curiosity, I opened up the SSDI site, and found my cousin Jimmy had been dead for seven years. His brother Jack died a year later. Where cousin Marie is I have no idea, since I never could remember her married name. And this morning I finally understood that those three people were what I leaned against, knowing they were out there, somewhere. Missed opportunites, lost chances, all the way. I feel sadder right now about that than anything else.