Eventually the soreness stops and you miss it, feels like you didn't train hard enough.
I hear that. Though I'm not quite at the 300lb mark yet Hit a plateau at 205/210, but going below parallel.
Then again, if you've taken a break, I hear that SL is a great way to get back in the game vs. continuing on with your existing program. Once you hit that first plateau again, you go back into your old program.