I was generally a pretty spoiled, six years younger sister, so the one time I was not treated fairly stands out pretty strongly in my recollection.
Elder sister was v v keen on children and had built up quite the babysitting practice. When she went off to college aged 18, I aged 12, took over some of that babysitting. I had no experience with children and always hoped the children just stayed asleep and didn't go back to any who didn't leave the children asleep in bed.
DSis came home in the summer with a boyfriend. I was always the first to answer the phone at home. One of the families phoned early in the summer, carefully asking whether anyone might be available for babysitting. Carefully not expressing a preference. It struck me that it would be nice for DSis and her boyfriend to have a 'night out' together so passed the job on to her.
I didn't connect this with the oddness that started one evening. It turned out that DSis was trying to avoid me knowing that she and boyfriend were going babysitting, assuming that I would be cross and jealous that she and not I had got the job.
But ... I stammered .... wanting to point out that I had indeed had the opportunity and had thought it would be nice for DSis to have the job and not that the family had expressed a preference for her.
DSis was so convinced that I was choked up because I was jealous, never entertaining the idea that it might have been me (for a change) being 'nice' and was trying to console me ... that I gave up trying to explain.
Goodness, it rankles sooo much to this day. And no wonder she was always kind and me ... not so much. I suppose you tend to do more of the things you get rewarded for.
I know I really should get over it but ... it was sooooo unfair not having my kind deed recognised. Sigh.