It only looks that way from the outside: "Here's what we know about Tyrannosaurus Rex"
Then, scientists keep working: "Hold on. Were they social? Here's some new evidence..." "Hold on. Did they move more horizontally? We hadn't thought through tail positions..." "Hang on, what's your methodology here? What just got found at the dig last summer? Have you considered this other modelling technique? What insights from comparative anatomy?" And so on. Discussion, re-evaluation, new metrics, chats over beers after the conference... Eventually, some pop-culture magazine says:
"Here's what we *NOW* know about Tyrannosaurus Rex!" And someone who wasn't involved in the in-between steps thinks "That happened without notice!"
Part of the fault may lie with how science is taught to kids in middle-school. Another part lies with certain elements of our culture *cough* which are actively hostile to higher-order intellectual development.
Can you give an example of theism changing without notice? All the examples I can think of regarding theism changing seem to involve social and philosophical pressures, discussed and explored within the religious community in question.
As the exception that proves the rule, when Hinckley denied on national television that we couldn't become Gods and have our own planets, and blindsided all of us who had been taught that from the pulpit, and, in our classes, since birth, *that* was a change without notice.