Just wanted to share something that I'm noticing at the moment.
As background, I've realised over the last year or so that I struggle to perceive and explain what I'm feeling emotionally, and, in comparison to how I was 20 years ago my emotions are pretty flat most of the time (I've put this in a box labelled Alexithymia secondary to Autism Spectrum Disorder). I used to get quite strong nostalgic / wistful feelings for example as autumn approached, or for example I got very sad and frustrated when my first marriage broke down and I had to leave the family home and my children and accept that I had failed at something, or I used to get quite excited at buying a new motorbike. Currently, little seems to provoke strong emotions though I'm generally happy and I did get excited about my ADOS appointment.
What I'm noticing at the moment is that something relatively trivial will happen, for example I bought something relatively inexpensive that has a minor fault and it disappoints me; that feeling of disappointment then stays with me and I only periodically remember where it came from. When I realise this, I'm a bit annoyed because the original event doesn't justify the feeling and it's tarnishing my day unnecessarily, but it is difficult to shift it.
I'm just mulling this over out loud - it's not a big issue even on a scale containing only "first world problems" but it caught my interest. It's like my feelings at the moment have low inertia; easily influenced, but of little consequence.