My own personal experience is virtually any major plans I had were diverted by external life, possibly the only exception was when I left a job as the stress level was too high and I was about to finish a new course opening up a different career.
To explain more details, half our lives depend on other people's decisions. We can choose a new career, partner or other things, but other people do the interviews, exam marking and accepting offers of dates etc. You can move house but your problems follow you wherever you go, and they need fixing first before you move for a change of life or they will still dominate your life. Then when I've got jobs I never had an idea how long they'd last, you can shift everything for a new one and get made redundant after a week as I did, and when I left the one I mentioned it took me 18 months in the end to find a new one doing something I did before I even left school as I had no other offers. My whole life, including choice of courses has almost been all by circumstances and regardless of my own plans, and if I thought there had been ways to keep it more on track I'd use them now but still not aware of any. But around half the situations life forced me into were little better or worse than what I'd originally picked, once course was out of my depth and guided by them to one that wasn't, and another was simply too demanding as evening classes and had to switch to another totally based on the hours and cost and location. It wasn't at the level I wanted originally but in a subject far more suited to my original career so pretty much broke even on that one and only ended up in my first choice by chance and not planning.