time management model

I am working on using thought work to better manage my time and build trust with myself. A model I noticed that comes up a lot is:

C – 10 items on my ‘to-do’ list
T – That’s super manageable. I’ll be able to get that done without a problem.
F – free
A – mind wanders to other things I’d like to do. I avoid doing the things on my to-do list. browse the internet. Take a nap. read. Talk to my boyfriend. buffer activities.
R – the items on my to-do list do not get done.

I know that Brooke’s method says to schedule everything on your calendar, which would avoid this cycle so maybe it’s silly and avoidant that I’m so curious about this model. I’m interested to understand it because this is the first time I’ve done a model and not seen the R prove the T and would love some help understanding. Seems like not feeling stressed and believing that I can accomplish the items on my to do list would be a productive thought. But it just does not play out for me.