Kinda-sorta the premise of the anime Frieren.

I had a character who's backstory wasn't too far off from that. The career changes weren't entirely voluntary, though, and usually were because he had suddenly lost all his money and needed to go adventuring again to rebuild his wealth. By the time the campaign was set, he was close to a millennium old, borderline senile, and making some very outrageous claims about things he had supposedly done in the past, like getting into a bar fight with Selune during the Time of Troubles or having once dated Lolth.

Like, you were a wizard 100 years ago, but then spells were super different and way less powerful, so now you get to relearn the newer better spells and casting techniques.

That's an interesting (and very Frieren-esque) bit of world building. But it does run contrary to the generic D&D settings/multi-verse, where the same set of spells have existed for centuries and across a multitude of worlds.

"When I was your age, you needed to know 9th level spells to cast fireball" is a cute crotchety one-liner. But it's not going to make any sense when you find a 2,000 year old spellbook with Fireball at the appropriate 3rd level slot. The DM would have to do a whole mess of retconning of an existing setting / pre-written material to make it work.

I imagine it’d be like learning to programming 50 years ago and then starting again now

As someone who did learn programming roughly 40 years ago, there are definitely differences. But an if-statement is still and if-statement and a function is still a function. The libraries and syntax can change, but the basic commands are still fundamentally the same.

I would note that modern programming-as-analog-to-magic would be more akin to everyone having a magic wand in their back pocket to do a set assortment of 3rd level spells per day which they don't even really need to think about other than the command word. Meanwhile, you've got this ancient elf flipping through a spellbook and spending an hour every morning re-memorizing a boutique list of spells nobody has thought to make a wand for in half a century.

Also a very interesting spin on a D&D-esque setting. But hugely divergent from printed materials.

Maybe he's a trust fund elf from some royal lineage?

Mom and dad have 900 years of savings in the college fund.

The value markets of men is a circular process of overproduction and scarcity. The bare-essential trinkets of yesteryear can often be exchanged for today's luxuries.

It's like Pokemon. You only get four skill slots.

I think I might be that kind of elf.

Further context, assuming the ruleset governing the OG Baldurs Gate games was true to the tabletop (I know they sort of kludged AD&D and aspects of 3e together). As the above said, a dual classed human "retires" their original class, and then begins to advance in their new class, essentially starting over from level 1, with only the hit dice and HP of their original class rolled over (you cannot access any of the class abilities you learned while advancing your original class). However, once your new class level is superior to your original class level, you can now access both skill sets.

It's a very strange system, and I am curious what the fluff reasons surrounding it are, if anyone has any insight into that edition.

1/10th life Crisis

Be sure to throw “spoon-eared fuck” in there too.

If you want something truly ancient and out-of-touch, you can easily just set it 15,000 years ago instead of 1,500 and no player will bat an eye or even notice

I am currently doing world building for a ttrpg campaign, and recently I did try to set an ancient empire 15,000 years in the past.

The basic idea was that empire A existed 15,000 years ago (them existing while the world was still covered in ice was important to the aesthetic), then they would be wiped out by empire B some time later, only for empire B to be destroyed by a great calamity. I wanted for there to be remnants of empire B still hanging around in the form of people who still worship a few of its god-kings and groups of people who still try to preserve its knowledge and maintain its infrastructure without fully understanding most of it.

The latter group was based partially on the Catholic Church preserving records after the fall of the Roman empire and partially on how the core of the Jewish religion was able to maintain a continuity of information and tradition over vast stretches of time even in the face of mass migration and social upheavals.

The problem was that I underestimated just what a vast gulf of time 15,000 years is. For one I was struggling to fill in all that time with events, and for two I realized that this knowledge preserving group would have had to existed for way longer than I was originally envisioning. Not only would they be older than the Jewish religion, they would be older than ancient Sumer. In fact you could take the entire history of the beginning of the Sumerian empire to the present day and fit it into that span of time twice over.

In the end I had to invent empire C, which refurbished some of empire B's infrastructure before collapsing themselves, as the actual origin for the knowledge keepers. And even with that I still had to move the timeline up by thousands of years.

It’s also not any less awe-inspiring to have people who lived in an important time period. We still have living veterans of WW2, and WW2 is no less important or intriguing

The problem with that is that it would really change the dynamic of how non-elf civilizations would develop. Unless the elves are extremely insular, and even then. How do you have a plotline involving the player characters needing to delve into an ancient tomb in order to discover whether or not the current ruling family are the legitimate heirs of the kingdom when you can just ask an elf? How does the world get into that situation in the first place when you can just ask an elf?

I have two friends who take turns running DnD 5e campaigns in a shared setting who have made elves entirely extinct for that reason.