Knowing what we know now, what would we do differently during the time before we retired? Maybe more importantly, does it matter? There is no "back to the future" option. The life we have built has led us to this point.
I would argue that knowing what we might do differently has two positive results, one for us, and one for those following in our footsteps.
For us: we are still a work in progress. Life is about change. There are ways we approach things or make choices in the future that will affect the quality of our retirement.
For those who have yet to retire: learn from our mistakes and choices. See what experience has taught us. Pick what fits your life and avoid what doesn't.
With that setup, here is a (incomplete) list of what I would tell my younger self, remind my present self, and pass along to those coming up behind me:
1) Don't fall in love with the consumer rat race
2) Save even when you think you can't
3) Good friends are worth more than you can imagine
4) Your health habits in your younger years will catch up with you
5) Work is what you do, not who you are
6) The Beatles were (mostly) right: love is all you need
7) If you lose your good name and reputation you won't get them back
8) There is no shortcut to success
9) It may not seem like it now, but life is very short and the end comes much too soon
I wondered if I should prioritize these nine things, putting them in order of importance. Try as I might, I couldn't. Every time I moved one item up the list, then I decided that the item just below it was just as critical to a happy, fulfilling life.
So, I am taking the position that all nine would be equally important to my younger self and remain vital to me today.