If you think about, since the MC has no talent and needs complete fundamental understanding to improve himself, then when he teaches others using that gained knowledge, those disciples could then drastically grow at tremendous speeds because those teachings don't include vague understandings such as feeling, but a true description.
Judging from that silhouette of their informant, its pretty obvious to see who he actually is. So either he has also regressed or already originally had a way to peer into the future.
Now I really wonder what was the main reason for their break up, because by this interaction, it can be seen that they have deep affection for each other. Was it simply because the MC could not keep up with her GF's pace?
He must have a logical reason, and one that can enact a stronger impact on Duke Icarus, since he too was a victim of his deeds, so Jerome has a right for revenge