Like everyone else on this earth, there are many things in my life I wish I had never chosen to do, or for which I wish I had followed a different path, or wished something hadn't taken nearly as long as it did to work out. Life is full of "what ifs" and "I wishes" and if we dwell too much on them, we're doing a disservice to our present and even our future. People like to say 'we all make mistakes' and while it's true that it's human nature to make poor choices, if you think about it, are they really mistakes or poor judgments? In hindsight, maybe they are, but at the time we do/don't do those things we so wish we could go back and change, they are right for us (even if they're ultimately bad for us). I believe that everything happens for a reason and sometimes it all really sucks, but whatever is happening in our lives at any given time is what we need when we need it.
Someone very close to me likes to argue that this belief is silly as it means our entire lives are planned out in advance for us and thus free will doesn't exist, but I don't agree. I believe that before we come here in our present incarnations, we do plan things out. I like to think of it as a brief outline of what we desire to achieve soul-wise in this incarnation. Are all the details laid out? Of course not, but the essential bones are there. And when we get into this life and begin to really live it, there are options, paths and crossroads at which we need to make the choices that will move us in one direction or another. Regardless of whether or not we've forgotten what it is we are meant to learn this time around, those "choice moments" are presented to us and we either go the right way for that previously drawn up soul outline or we go another route; a route which may take us to the same place albeit in a very roundabout way, or one that has us miss our "moment" entirely and perhaps learn other lessons or even nothing at all. At those times we either have to hope for another moment in time when we can make the needed decision or risk having to repeat that part of our soul's journey once again in another life. But regardless, everything is in its time; perfectly in its time. And everything we do and say and act on happens when it is meant to, even if it takes you half a lifetime to realize someone you've tried to love is not a very nice person and needs to be jettisoned from your life. Or you were meant to be a missionary and not a school janitor. Or you're never, ever going to master the violin enough to make it a lucrative career despite decades of hard work.
As humans, it's in our nature to regret that which isn't perfect to our eyes and to be self-critical to the nth degree, but life isn't about easy or perfect or timely, nor is it about our own feelings of regret or our own shortcomings we wish we didn't have, it's about the end result and that- despite our fears of having wasted so much time- is going to take just as long as it's meant to.