9. Galactus Made Him Lose His Human Form - Fantastic Four #175 (1976)
In Fantastic Four #167, Ben absorbed some of the Hulk's gamma radiation, reverting to his original body. This moment was a dream come true for Ben since he felt like he could finally reclaim his humanity.
Because the gamma radiation caused Ben to lose his superstrength, the Fantastic Four replaced him with Luke Cage. But when Ben admitted he missed playing superhero, he asked Reed Richards if there was anyway he could rejoin the team.
After some brainstorming, Reed built a stoney exoskeleton for Ben that granted him the same strength and durability he had as the Thing. Because he looked normal but could still clobber giant robots and aliens, Ben felt like he finally had the best of both worlds.
Of course, it was too good to last. While squaring off against Galactus, the Devourer of Worlds blasted Ben with a laser, turning him back into the Thing. Sadly, this was the first of many, many times where Ben was given false hope. No matter how many times he reverts to normal, something always happens that forces him to change back to his rocky form.