Being back in a solo development environment after many years in an agile environment with required pair programming can be quite a change. I’ve been quite used to pair programming and influencing my partner to check in on each passing example. In a solo environment this can be a little trickier, and even I have succumbed a few times to letting the sun set on un-checked in code. 
And being in a solo development environment has really made this easy to let slide… I found myself deleting code and starting over a few times in the past month because I let myself do work that I didn’t check in before the end of the day… mostly because the old adage is true… when you let yourself do work and not check it in for multiple days, the code in version control will tend to drift in a way that makes check-ins difficult and leaves you feeling like you’re not getting stuff done because you have uncommitted code on your machine.
So it all still holds true for me… code just does not exist at all if you haven’t checked it in yet. 
Also remember – if it ain’t tested, it’s wrong.
Not just wrong… completely broken.
Ive had a self-built version of Notepad that supports saving as UTF8 w/o a BOM (byte order mark) since 1999. Never checked in (no approval to do so!), but I’ve kept it up to date with each new version of Windows. And I use it all the time so I know it exists!