Every explanation fits the past
I'm not sure where I heard this, but it beautifully summarizes an important issue:
Every explanation fits the past.
In other words, any theory can be molded to agree with previous observations. A theory's usefulness and validity depends more so on whether it can correctly guess what will happen in the future, whether it has predictive power.
edit (2026-01-30): Although I'm not certain, I vaguely remember the quote coming from Scott Adams, who was interviewed on a podcast I listen to. Scott Adams had some good ideas, lots of bad ones, some crazy beliefs, and some strange, unexplainable political allegiances. That doesn't make the observation any less valid. Life is messy.