…you give the example of worldly events or traditions and apply the same logic to the the remembrance of Jesus' death. I understand and it makes sense logically. But
I'm trying not to follow that logic and go by what the scriptures say, without reading into the text, but connecting the dots and trying to find evidence of how it was observed in early congregations. Using scripture to examine scripture. So what I think doesn't matter, because my thinking will change according to where that evidence points me to.
regarding your statement
I'll say that if the breaking of bread is done at every meeting, it significally increases the importance of every meeting. But I digress.
I found that, according to Justin Martyr, the practice was a weekly event, on the first day. Acts 20:7 seems to support it:
"On the first day of the week, when we were gathered together to have a meal, Paul began addressing them, as he was going to depart the next day; and he prolonged his speech until midnight."
I listed more verses in previous posts, which also seem to confirm this.
Didache also states that eucharist (also known as Holy Communion and the Lord's Supper) was the essential part of Christian worship gatherings. Didache was recognized as one of the most important manuscripts of the early Christianity because it was written before church hierarchy was firmly in place and was very close to the Jewish Apostolic Age.
Now for the JW practice. Please note that this adresses the "annointed only partake" part since I am still looking for the "when the annual observance started" part.
I found that how the Memorial is practiced today most likely originates with Rutherford (I'm still researching this). It looks like it's closely connected to the changes in teaching who Other Sheep, Great Multitude and Jonadabs are. In March 1, 1938 Watchtower, p.75 it's stated:
"Am I of the anointed who are privileged and duty-bound to partake of the Memorial, or am I a Jonadab, who cannot partake of it?"
Now, as I am reading this WT and seeing that it's drawing the parallels to passover a thought occured to me: If the passover was a feast that was to be eaten by all Jews how is it then that only annointed eat the emblems? It seems to put an emphasis on who eats it instead of why it's eaten.
In Exodus 12 the reason why is stated: 26 And when your sons ask you, ‘What does this observance mean to you?’ 27 you must say, ‘It is the sacrifice of the Passover to Jehovah, who passed over the houses of the Israelites in Egypt when he plagued the Egyptians, but he spared our houses.’” Then the people bowed low and prostrated themselves. 28 So the Israelites went and did just as Jehovah had commanded Moses and Aaron. They did just so.
If today it's the spiritual Israel that are meant to eat, then it would mean that Jesus' sacrifice was only for them, and that doesn't make sense since Jesus' sacrifice was for all mankind. But that brings the point from one of the previous posts that other sheep are part of spiritual Israel too. I'll stop here before it gets out of hand

It's a big topic and I'm excited to look more into it.