Castiel in "The End" and "Reading is Fundameltal", does anyone notice a similarity?

loool i did notice a slight similarity too. castiel told sam that 'sam's burden' actually helped him with his own guilt about taking souls from purgatory, so I'm not sure about that part, but cas is almost detached from the situation in RIF, he doesn't feel the need to fight, opposed to TE, where cas still follows dean's orders (when he isn't stoned), despite how dangerous they are. so i would say, the basis for the character seems very similar, but the actual execution of it is a bit different.

It was actually one of my first thoughts after the episode ended, but the more I considered it, the less similar they seemed. Insane Cas is more like a five year old, while 2014 Cas was still capable, realized the issues, and was willing to help but simply felt as if he lacked the skill set to be of use in the group. I think the big thing that initially led me to my earlier conclusion was the amount of humor both versions employed, but if you pretend that they are separate people showing those personality streaks they would appear less parallel. It's just the humorous quality isn't generally as slapstick with his various characters... (well, that's my opinion at any rate)

Kind of.

In The End, Cas was a stoned/drunk hippy who was living in the end of days, and pretty much didn't care about a whole lot anymore at that point. In Reading is Fundamental, Cas was an insane which was caused by taking Sam's "burden" and being plagued with visions of Hell. This Cas did care, he just avoided confrontation at all costs.

It was similar behavior, but caused by different reasons.