I don’t think this is true, or at least not true in all cases.
From what I’ve seen and talked about with friends who have poor time management skills, a big problem is they get distracted and don’t stay on task. Thinking about the clock doesn’t really enter into it in that case.
There is no clock in my head.
I’m a little confused what you mean by time management skills, now, too. Can you give an example of a scene that required them, and how it would look for someone with good skills and how it would look for someone with bad skills?
Like, I have a friend coming over around noon today. I need to shower and get dressed before they get here. That takes like half an hour. I might just set an alarm on my phone for like 11:15 so I remember. I’d set it to 11:15 to give myself some extra padding. I know I shouldn’t do anything that might take longer than the time available, like go for a long bike ride or start playing a video game that can’t be paused.
There’s not really any intrusive thoughts here.