Some self reflection has brought up interesting questions of late about the nature of agency as it applies to self-improvement, motivation, and those types of things.
There are goals in my mind that circle my awareness like sharks, but without the negative connotations, so lets say dolphins instead. These represent all the things I would write down as a list of desired achievements if prompted, be they long or short term, grand or mundane. The more focus I give to a particular dolphin, it circles closer and closer, eventually coming over for a look, a pet, a bite of fish (I've never met a dolphin, this is a feelings-based metaphor, not a good one). The interesting thing is that no other action on my part aside from that all-important focus over a number of weeks or months appears to ultimately trigger this new event in the relationship with my self.
Now, when the inclination to begin some new endeavor rises up in me, but requires buying things, I am immediately suspicious that I am simply a cog/victim of consumerism despite the legitimacy of tools or consumables as a starting cost for many or most things humans do. I deal with this suspicion on a case-by-case basis, and as a relatively frugal person, am not so worried about it.
The scent of existential crisis is on the wind however when you ask "why?" and "why now?"
I have never been in shape in my life simply because my hobbies have never been ones that promote full use of the body - with the exception of some martial arts as a child - and as long as I managed to stay within certain aesthetic boundaries, the desire for fitness has always been quite foreign. Despite that, I've started counting calories again, bought some weights, a bench, I ride my bike, hike, or push a lawn mower around for 10-15 miles each week.
It's bizarre. This is a pleasing development, but its timing is a ultimately mystery to me.
I think the "why" of it is a combination of factors, the following are a small sample:
I think none of these are the product of any original thought, personal drive or agency on my part. They all have an external source. That said, I have over several months ever so slowly surrounded myself with tiny influences that absolutely promote these things. This was on purpose. Why did I do that? Cause and effect ad infinitum, I'm afraid: too hard to tell.
This memory comes up constantly, of my teenage self, my dad, and my newborn nephew all waiting in the car. We're watching this baby go through its full range of emotions and expressions at a rapid pace, as babies do, and my dad says "That's all we are, only with more and more layers as time goes by, but that is always there."
Anyway, "know thyself", but don't be afraid of the absence of freewill or the malleability of your ego because these can't be helped and are mysterious concepts at best. Instead, build relationships with your inner dolphins if you choose to see them as such, because they want to help (your brain created them for that).