I know better, so why am I an idiot?

I've been researching literary agents. Yes, I know I already have queries out, and yes I know that I shouldn't send to every agent in North America at once. Still, to have a real clue about the agent I'm attempting to woo with my query, I think it's only fair that I put a little leg work into it first. Besides, if my queries don't land any love, it's good to have a back up plan. That way I don't just sit around wallowing in self pity and doubt, I already know who I'm going to query next. It's unusually proactive of me, but  research is one of those things that I just do. Yet, there's this problem with researching literary agents.
I pull up their blog, and there they talk about the people they've signed, and they often have links to those author's blogs. Normally this is great, but then, like TV tropes, I find that I've been reading other writers' blogs all day without writing. And what's worse, I start to feel intimidated about writing, as though their successes diminish my ability. It's like reading these blogs erodes what little confidence I have about my own writing.
And I know better. I know that their success does not make it harder for me to have my own, so why do they scare me? Why does reading a great book always convince me that I'm the worst writer on the planet? And then I go back to writing, still convinced that my stuff is never going to sell and I'm never going to get an agent.
I guess one of the prerequisites for being a writer is to have a masochistic streak.
Well, I've got that covered.