Investing Question for Novice

Hey there folks!

I hope this is the right sub for this...

I (31 year old, male) am looking to set myself up for success and retirement, and have been reading lots of blogs and books about future planning. One of the main things I hear (and read) is that "the first 100k is the hardest part" and that from there momentum and time will begin working in your favor at an exponential rate. But, I am not sure what that means...

Does that mean the first $100k in your retirement savings aka 401k/ 403b? Does that mean first $100k in stocks outside of a 401k/ 403b? Or does that mean a $100k value in some other manner like stock holdings outside of non tax advantaged vehicles?

I have worked both in the for profit and non profit industries so have both a 401k AND a 403b that combine to a value of $103,000. Just over $100k. Yay! Does that mean I have hit the elusive first benchmark of $100k?

Moving forward, I will continue to push as much of my income as possible into my retirement but I am curious if there is something else I should be thinking about. Any clarity or insights is appreciated.

Thanks y'all!