Tom, from your other posts I perceive that you've got a HUGE jump on most regarding living within your means, debt management and investing, regardless of age. You already indicated your familiarity with compounding interest and "time is on your side", so congratulations!!! Now go enjoy the next 25 years living your life, and keep doing what you're doing...the rest will take care of itself with just one caveat....don't get DIVORCED
! There's a "rule of 72"....take any projected return, divide it into 72, and that's how many years it will take to double your investment. Let's take 8% for example (and a more realistic rate too), you'd double your investment every 9 years, and so on. I was having too much fun "way back when" to worry about money (still don't), but you're already on the right track.
ps: If you're happy w/ ML, might I suggest leaving your current 401K in place when you eventually change jobs. Some folks like to rollover/consolidate their 401K/IRAs, etc. but I like the flexibility (IRS rules) that comes with not doing so. (One can still have "everything" under the same borkerage house, etc. just keep the individual accounts "distinct".) In a nutshell, the x you contribute now (along with co matches) can easily be 10x in 25-30 years. Good luck...but you're not gonna need it