As gumlines recede
the wind loosely waves the teeth.
I had a couple colleagues who I'd trade haiku with occasionally. Most of mine were the result of killing time and engaging brain during SoCal slow_and_go drive time. Some good efforts. Mostly bad. :-) I might dust a few oldies off and see if it stimulates any fresh creativity. Good memories all.
Jobs change. People move on. New people replace them.
You're never as close to the newer hires. You end up surrounded by hundreds of people and not feeling connected to any. Tempermentally those who hire into our (now) large stable/mature company are different from those who came in as startup/small company hires. That difference in the company's life cycle attracts a different sort of person.
The newer hires came to the company during a different era (mature vs startup), with different expectations, with a different level of intensity in their work (and play).
A bit of morning melancholy in that perhaps. Oh well. When things stop changing you're dead. So considering the alternative...
Change is the only constant.