There are just too many opinions for the bullish case as well as the bearish case. After living through 2000 and 2008-2009, I'm sick of hearing the talking heads make predictions.
Like many here I started saving for retirement with my first paycheck.
For me, having a plan and sticking to it was key to getting through the bubbles and now I'm within a year or so of pulling the plug and FIRE....50 to 51 is my goal.
Didn't take unnecessary risks that could have devastated savings.
Didn't fall into the trap of being too conservative (making decisions based on fear is a bad investment strategy).
Didn't try to time the market.
Ignore the noise, add to your positions regularly, stay the course, rebalance, keep costs low and adjust your risk profile as you get close to the time of needing the funds. I hear this advise time and time again...good news is, it works, at least it has for me (so far).