&gt; But the biggest thing I&#x27;ve noticed? What look like big opportunities, vanishing in the rear-view mirror of age.....So you get locked into whatever track you set yourself running down twenty years earlier. Changing is hard because you have less of a future ahead of you to change for.<p>Or even if you&#x27;re not changing track, if you&#x27;re developer ~20%++ of the track changes on you every year, can you maintain this pace when you&#x27;re older, maybe with a family, and don&#x27;t have the time or motivation to learn yet another way of doing &lt;x&gt; for the umpteenth time.  For younger people I would recommend keeping a close eye on that situation over the long term and if possible have a plan B if you want to get off the treadmill.