To Eli it was sometimes weird that people didn't take the sort of precautions he did. Although then again, few people were into the sort of things he was and his work and interests tended to require a bit more security. "No, not a vegetable, at least not intentionally." As a tool, a pensieve was a relatively harmless thing. It allowed a third person perspective of memories, any sort of complication came in acquiring the memory, which is exactly where he was running into a bit of trouble.
"I seem to have stumbled upon a sort of curiosity. I have been having the reoccurring nightmares and while I am able to pull a clean memory of the nightmares from the first night, I seem to be having some trouble with those that follow." As if to prove the point, he accessed that particular memory. Floating to the top was a watery image of him being surrounded by dementours, losing his mind and his soul in the process.
This was far more than he would have willingly told Samara, but it was different with her. She was having the same nightmare as him. What he needed was someone outside of their connection. While it would have been quite nice for Roger to also be having the reoccurring nightmares to examine the issue as well, he could work with this. "Although before we get to that, how familiar are you with how one of these works?"