In the US at least, many large employers automatically create 401ks or IRA’s for their employees and contribute a portion of your paycheck to it.
After I graduated college, my first job created a 401k and started putting 1% of my paycheck into it without telling me. The job didn’t let me set it to 0%, forcing me to research 401ks and retirement planning. This led me to raise it to 15% and start investing.