Actually, he's trying to rationalize everything. He's just afraid as shit truth be told, so it's easier for him to distract himself with thoughts.
But even before anything happened he was just complaining about everything.
"oh my sister is annoying" "oh my life is boring" "work is boring" "it rains too much"
Meanwhile his life is actually fine, he's got a nice place to live, a sister that at least cares enough about him, a girl who likes fucking, no particular money problems.
but even with all that he's still got bad attitude with everyone.
Ok his mum isn't around much, big deal, my dad died years ago and my mum already has had cancer twice and I basically raised my baby sister to the point I was her legal guardian until she was 18.
And plenty of people have had lives far worse than mine.
This guy [MC] just whines and is rude with everyone.
By the way, I'm not saying its bad for the story, just so long as its intended, I'm just saying that so far I find the MC utterly unlikable.