Well in his son's TrekNation doc from a few months back, we saw footage of him appearing forgetful during an interview. Not sure what the cause was, though.
To be fair though, with or without
Gene it was probably going to take some time to iron things out with TNG. Launching an entirely new Star Trek series with a whole new cast would have been a huge, daunting task for anyone.
The fact we got as many great episodes in that first season as we DID is kind of amazing, if you ask me.