I also notice a marked decrease in anxiety or tiredness after meditating. While of course that could be a placebo effect, almost all other things I did to deal with anxiety (including CBT) didn't really do much, despite my belief that they would.
I've talked to a number of people who didn't really see the point of meditation, only to discover that what they were already naturally doing was essentially a similar thing. Or they just didn't feel the need.
Similarly, I've met people who can smoke cigarettes for months without getting addicted, people who can remain calm in incredibly stressful situations, people who just don't understand the concept of 'boredom', etc.
Perhaps you're just one of those people who don't need it, and I'm kinda jealous of you if that's the case!
PS: It is sad that this marketing/self-help-book/guru/training etc. hype around "mindfulness" distorted the original simple meaning of the word mindfulness.
This then gives you the power to manage them better in a few ways, including that thoughts are just thoughts and you don't have to act on them all, and actually be aware of how you're feeling and what actually caused that and how to manage that feeling if it's destructive.
I'm also a bit skeptical that you actually are mindful of yourself. When you actually do it and realize how it works, it's pretty amazing. I certainly didn't think "well, that's just common sense". When you actually do it, start observing your thoughts and feelings as separate from you instead of consuming them and getting caught up in them, it does bring calm and a feeling of refreshment.
The best thing I use mindfulness for is stopping a destructive cyclical worry. As an example from the past, say I'm worried about a client not having paid his bill yet, I know they're having cash flow problems and I worry I exposed myself to too much risk. What can happen is that thought can spiral and keep popping into my head, intruding into my day. It might create a cascade of thoughts, what my bank balance is like, how might I get a partial payment, is it too early to phone, should I look for another client, what will I do with the existing work, should I have asked for better payments terms, etc., etc., etc. But the worst part is, I would have that exact same chain multiple times a day. It intruded over and over, until the client would pay (predictably) late again.
But none of that helped when it was firing, it's not even that late yet. It just made me stressed and stopped me from getting what I needed to get done that day, sometimes I couldn't just place it aside.
Using mindfulness, instead of consuming that thought and worrying about it, I can just look on it as a thought.
Maybe that is mindfulness, I don't know. It just feels very far removed from the mysticism and mumbo-jumbo I was confronted with, which honestly just added stress, rather than mitigating it.
No magic, pretty straightforward. But an enormous amount of suffering is caused by us thinking/worrying about bad shit.
Now if you are more aware of what you're thinking and can change what you're paying attention to you can make your mind spend a lot less time worrying about shit that makes you miserable.