This question was inspired by another one.
Shortly after freeing Neo from the Matrix, Morpheus tells him:
We never free a mind once it's reached a certain age. It's dangerous, the mind has trouble letting go. I've seen it before and I'm sorry.
What's the maximum age at which Morpheus would free somebody?
I'd say Neo was freed in his late 20's to mid 30's. I'd guess that Cypher was freed in his early to mid 30's because his character looks like early to mid 40's and he was freed nine years earlier. It's possible that one of the reasons Cypher did what he did is that he had trouble letting go of the Matrix. Maybe he was too old.
Please provide answers based on actual sources. (e.g. - screenplay, official novelizations, or comments by the producers)