This is so cartoonish, from how being an adult suddenly unlocks all chakras, and now how this guy is a noble straight out of an isekai trying to bully the commoner OP MC.
I liked this one at the start, but it's been circling the drain ever since the blonde guy showed up.
I dunno. When I was in school, I struggled a lot because I had too much on my mind. Too many unimportant things, really. I did well, but it was a terrible life. Now that I am much older, I can focus much better, and have a better grasp of who I am. It helps a lot. He has lived an awful life, and understands the cause-and-effect of things like studying and goal-setting and its effect on his adult future.
In addition, he is socially much better equipped. A high school loner has a lot to overcome as an adult, and he's gone through all of that. Now he can navigate things like conversations and social interactions without having to guess at what works. He has also been badly used by his employer, and has learned how to recover from mistakes. Just the ability to say "I made an error. How can I fix this?" was an insurmountable barrier for me, and kept me back for years. I tried to cover for myself and repair things in secret, which worked out badly sometimes.
Finally, he's already seen many of the things he is being presented in school. That familiarity can go a long way.