In this episode of I can't believe that the author isn't a H artist, we have "very BOOBA fan service and BOOBA and BOOBA and thighs and exercise". Honestly, this shit makes me wanna change my life, get it back on track and exercise
I think he actually knew Hydrogen was H, but the problem is that he just temporarily forgot because he was, uhm, extremely distracted and while blood flow was likely improving, most of it was going to the wrong head...