Disclaimer: of course, everything is a spectrum. To ADHD-people, caffeine has varying effects. Some get tired from it, others it affects less or not at all.
So what’s wrong with kg for weighing things, st & lb for people, miles for driving distance, metres for building things, C for temperature and feet for ascent of hills and stuff? That’s what a 70’s born UK kid thinks like. So 16:15 is said out loud, quarter past four, maybe rarely 1615, but never 16 o’clock and? No. O’clock is only on the hour. If it’s got bits on the end you say everything except the ‘o’clock’ But I love what you’ve done with ‘half-four’ to mean 3.30. I really enjoy doing that with my German colleagues.