Is it just me?

Why is it that I can listen to a recording and be moved to tears on one day and other times I can listen to the same recording on the same equipment in the same room and not be as involved?
Does anyone else experience this?
Is it the humidity, barometric pressure...what?
It's just part of the human psyche. Everything isn't always the same in one's mind.
"Is it the humidity, barometric pressure"

How about high Pollen count (;-

It's simply human that your emotional reaction to a recording will lessen as you hear it more.
Another overlooked factor is the quality of your system's electric supply. Generally speaking, a system will sound better during low grid demand hours (late evenings) and worse during high grid demand hours ( daytime weekdays).
High temperatures can also decrease a system's sonic performance due to the extra demands on the grid from home and business air conditioning usage. All of the home and business electrical equipment connected to your neighborhood's electrical grid and any noise this equipment introduces, between the power generating plant and your home, does nothing but degrades the quality, and can even fluctuate the quantity, of the electricity supplied to your audio/video equipment.

I notice my system sounds best later in the evening when the weather is temperate. This is not meant to discount the other factors already mentioned thus far.

Mood, the day you had, the quality and quantity of wine consumed, fatigue, etc...
All of the above, plus maybe the day-to-day voltage swings from your incoming power to your dwelling. See about getting a plug-in voltage meter (not very expensive I think) and examine readings the next several times to see if there's any variation that seems to reliably correspond to your listening involvement issues. If so, you can then think about doing some homework with various solutions like power conditioning or voltage regulation or even power regeneration and the like. There should be at least some kind of level of solution for your particular budget. This sort of thing I describe is not uncommon and is usually referred to as the "time-of-day" effect, but it can vary on a day-to-day basis as well. Hope this helps.

Regards. John
It would appear that weather plays a large role, with wet conditions and low pressure systems being quite bad for the sound, the electrical grid most likely being affected. It would also appear early mornings and nighttime are better times for critical listening. It's difficult to prove other than by tracking sun spot activity over at the National Weather Service site, but sun spot activity might influence the sound, I wouldn't be surprised. Not to mention the myriad things we change in the system without paying much attention. What ever happened to keeping a log of changes we make, even seemingly innocuous changes, like arrangements of cabling, absolute level for the turntable or CD transport, etc.?
The emotion in music isn't controlled by power conditioning. It is conveyed through the musician and our state of mind at that moment. Otherwise, we could only be moved as such at a live performance. I've experienced it at various quality levels of reproduction- one such time was in my car in the 70s with an 8 track tape. Try as I might, that moment of feeling never happened again with that same song- even today with the vinyl version playing on my hifi; but I still remember that moment nearly 40 years later.
Tony, didn't mean to suggest that my post was the only possible interpretation of the OP. But, I know exactly the kind of experiences you relate to. In fact I think we all do...enough so that I imagined Mlman probably understood that as well and, likely as not, was originally prompted to post b/c he was wondering if there was some sort of technical reason for what he was experiencing within the context of his own system...of course, I could be wrong on my presumption...Mlman??
Point taken. My system can give me goosebumps now and then which I think is related to quality of reproduction but the emotional connection is all about the musician, I think.
Different days, different ways of seeing things.

The electricity going into your components from your home's outlets can vary from day to day in both quantity and quality. Tyypically, audio and video components will perform best during non-peak hours (usually later in the evening) when the electrical demand from households and businesses on your local power grid are at their lowest.

I've never experimented with power filters or regenerators, but I can verify that my system sounds best in the evenings. My comments are not meant to discount the other factors, mentioned previously, that can also affect your subjective impressions.

Regenerators and power conditioners are a crap shoot. I've had several of both and now go straight to the wall with aftermarket outlets (take your pick). The one thing I will eventually have done is the installation of a dedicated line or two.
This will happen to me in the car the a stock fm radio, so it's not a high quality system here. Depends on my mood and how I'm relating to the tune that particular moment in time.

human psyche.
It's just you, in a sense--but we all have the same experience. It's just us, a subjective thing.
Migraines??? Lol...
I began to weep spontaneously a few years ago when I heard The Youngbloods 'Get Together' after not hearing it for many years. It was on my son's low-fi radio. Nothing to do with the gear, just circumstance.
The answer has to be in our neurology.
I think you need some dianetic auditing to permit your true Theta-personself to emerge. This could take years and be costly to fix. How much money do you make again?
Nhaudio wrote:
"I think you need some dianetic auditing to permit your true Theta-personself to emerge."

What's sad is that many people buy into this, sometimes into the 6-figure range.

While I don't recommend enriching the estate of L Ron Hubbard, taking a good Psych 101 or Intro to Behaviorism course at the college or CC level might provide some insights. Disclosure: I'm an Experimental Psychologist by trade.

Quasi-formally, Antecedent Vars (essentially your mood and physical state at the time; i.e., what you "bring to the party") AND the Independent Var (here the auditory/musical stimulus) AND Interdicting Vars (auditory distortions AND other external/internal distractors) Yields a Dependent Measure (How you emotionally "feel"). Changes in the any of the Antecedent/Independent/Interdicting Vars will affect the resulting Dependent Measure response.

Again, you might enjoy an Intro Psych, Behavioral Psych, or Psychology of Music course.
I, having multiple personalities, would have to concur with Dr. Courant's diagnosis.

I know my Billy Idol and Alice Cooper personalities never enjoy any of my clasical music as much as Johann, Ludwig and that goofy Tim do.

Just my 10 cents worth (2 cents from each personality),
Tim, Johann, Alice, Billy and Alice