There is a very odd, very good feeling when you as a programmer return to some technical task that you used to do – and you find that you do it better. For myself I am once again dabbling in RSS programming and it feels great. It was almost 14 years ago to the day that I started Feedster based on an idea that Dave put out there by linking to an idea that Dave Aiello had.
That one tiny mention on Scripting.com inspired me to hack together a truly awful RSS search engine that in turn survived a slashdotting and then picked up a co-founder, a CEO, angel investment, a move to San Francisco, real venture funding and actual staff.
It was, I believe, March of 2003 on a snowy night and now in January 2017 on another snowy night I am again writing feed processing code.
The technically interesting part here is that the operations I did poorly back in 2003 are now flowing and gracefully from my fingers as I work. Specifically I used to monitor feeds by doing a full fetch and then hashing the body with MD5 and comparing it to a stored value from the last time. This time I knew "Ok. Do an HTTP head and look at just the header values". Additionally I am using a far better toolset in 2017 (ruby / rails / elixir / phoenix) than I ever did back in 2003 (php).
If as an engineer you've never returned to a problem space after a long interval, I'd recommend it. Just seeing how you tackle the same problem after a long break certainly makes you think.