That must have been a rewarding experience! I made the mistake of memorizing the solution when I was a kid so solving the cube feels like a routine instead of actually solving a puzzle.

Exactly the same experience and feeling for me. Taught myself how to solve the cube during the pandemic but now all I know how to do is solve a cube in a specific order.

It takes the same amount of time every time and it doesn't actually feel like I'm solving it but instead putting it back to its original state.

My (young) kids got interested last year, so I learned the algorithms to be able to put it back for them.... And got kinda hooked myself! For me though, I don't have the sequence memory to be able to work it out from scratch. I have the logic, but have to write down each step and it gets very very slow. Learning the "algorithms" from online courses was like learning ballroom dance, for me, and learning increasingly quick and specific solutions for different stages is still satisfying. It's a physical / slight mental challenge, rather than a puzzle to work out.

If you want to recapture that feeling, look for Rubik-like puzzles in different shapes and work them out on your own. Pyraminx, Megaminx, Skewb, Square-One, Helicopter Cube, Gear Cube, Dayan Gem are names to search for among many others, or even just the bigger or unusual cuboids (like 3x3x4) if you've never done those.

Same. I learned the simple algorithms recently and now ot feels very underwhelming.

Someone was curious as to my method so I made a YouTube video. After a year or so of not solving I was rusty on my method, so my YouTube video taught myself how to do it again.

Same for me, except I was forty-something. I captured something of the experience after stumbling on the “duncan beach ball puzzle”. After memorizing the moves for the cube I read a lot about how a person could solve the puzzle (and ones like it) from scratch. So then I went looking for other permutation puzzles to try the technique. The technique was basically do some sequence of moves, then one move, then undo the sequence. After that notice what 2 or 3 elements swapped places in the permutation. Everything else remains the same. This was easy enough with the beach ball and the classic 15 puzzle. Give it a try!