A very odd story

I met a man once while out for a walk. "Tut, tut!" He would say, as he wandered this way and that. I saw him approach a group, "You there! Will you trade? I've got a lovely a nut right here. What about you? A nut for a jar of tuna?"

I didn't think this question was sincere, because I noticed that although nobody answered, great relief and momentary joy filled his eyes. I was very confused. Finally, he came to me and I asked him, "Are you okay?"

"Me? Never been better, just been made a little crazy.." he answered.

I inquired, "Who made you crazy?"

He replied, "No! Not who, but what!"

But he only chuckled, and said his familiar "Tut, tut!" I continued to press but all he gave me were even more tuts. His head had been in the clouds, it seemed.

Can you figure out what made the man crazy?

Hint

The answer reveals a bit of backstory for the "odd man," specifically, some place he has been. This answer is given not by something the man said, but rather by something recounted by the story teller. The comment by @msh210 is important.

• rot13("nygubhtu abobql nafjrerq, terng eryvrs naq zbzragnel") Aug 2, 2020 at 21:54
• is the rot13 text the answer or do you have to use it to get the answer? Aug 29, 2020 at 23:04
• @ShubhamGoenka it indicates how the answer is hidden
– user69943
Aug 30, 2020 at 16:17

Observation

His last question, "A nut for a jar of tuna?" is a palindromic sentence.

So perhaps what gives him joy and makes him a little crazy is

Uttering or happening across a palindromic phrase or sentence.

This is supported by

The fact he is always saying "tut tut", a short palindrome.

• Great observation. The palindrome is certainly not a coincidence. However, a closer look should show this is not in fact the answer
– user69943
Aug 2, 2020 at 0:05