* More than a fifth of the treasury bond debt owed by the federal government is owed to... none other than the Federal Reserve, which is part of the federal government. Every year, more than a fifth of the debt payments made by the US Treasury go to the US Federal Reserve, which dutifully sends them all back to the US Treasury every year.
* If you own any US treasury bonds (whether directly, in a 401(k), in some other kind of retirement or pension plan, or in an index fund), that's your share of the US national debt: It's the amount the federal government owes you.
* Every dollar spent by the government at home is a dollar earned by the private sector (who else?). Every dollar the government spends at home goes to private companies (healthcare providers, aerospace/weapons makers, government contractors, etc.) or to private citizens (government employees, military officers and their families, individuals receiving tax refunds, etc.).