I'm very dependent on clocks and schedules; if I don't know exactly when something is happening or when I have to be somewhere, I get very anxious, and if I don't know what time it is almost all the time, I feel disconnected from reality, like time has stopped or is fluctuating. It feels very disorienting, like I'm bobbing on a raft in the middle of the ocean, with no landmarks to orient my place or direction. I've worn a watch pretty much 24/7 from the time I was 13. I even sleep with it on in case I wake up one morning and forget to put it on before I go out.
Concerning your compromise, just telling your mom you're not interested in karate anymore shouldn't be too disasterous. If she's worried about you making friends or being social, you can just tell her you're comfortable where you are socially right now. Other than that, as long as you're on time for the appointments that matter, you can live disregarding time pretty much as you please.
Oh, and one more thing. A "compromise" is what happens when two people give up something they want to meet at an agreeable place in the middle. You're compromising by adhering to your mother's view of the importance of time and schedules, but what is she compromising on?
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"Survival is insufficient" - Seven of Nine
Diagnosed with ASD level 1 on the 10th of April, 2014
Rediagnosed with ASD level 2 on the 4th of May, 2019
Thanks to Olympiadis for my fantastic avatar!