Right, this is why opsec is something that you must always be doing.
Anything you say can be preserved forever.
Better to use short-lived throwaway identities, and leave yourself the power of combining them later, than to start with one long-lived identity and find yourself unable to split it up.
It's inconvenient in real life that I'm expected to use my legal identity for everything. If I go to group therapy for an embarrassing personal problem, someone there can look me up because everyone is using real names. I don't like it.