FYI: USE THE RIGHT tool for the job and you’ll get the best result. If you need to connect two boards, you could use a hammer and a nail or a screwdriver and a screw. Either methods work—and they’re certainly better than banging in a screw with a hammer, which I’ve seen tried. It was not effective.
Participants in 401(k) plans, alas, display similar behavior with target date funds, or TDFs. A TDF offers a diversified portfolio in a single fund, with the mix of stocks and bonds changing as you approach retirement. When used correctly, the fund’s asset allocation should be appropriate for your age—aggressive while you’re young and becoming more conservative as you age. There’s no need to trade or adjust the mix. The fund does that automatically. The evidence, however, suggests many people use TDFs incorrectly.