Fueled by the pandemic and TikTok, a market for content made by fathers has staying power. Meet the “Dadfluencers.”

Millions of workers open retirement accounts, then ignore or forget about them, leaving thousands of dollars unattended. Are you one of them?

One reason: You pay for it. And, despite what many Americans believe, it’s “definitely a misconception” that it will run out before you retire, experts...