Allegedly Jr. had a lengthy record including some drug offenses and something like a DUI / DWI. Naturally Sr. And Jr's records got crossed since they have the same First, Last, and Address, which caused Sr. many headaches including that we required a driving record check that would fail on a DUI / DWI.
Because, lacking a national identity number, the natural way to distinguish to people in a system when the name wouldn’t do is going to be age/birthdate or location.
I've also met two others with the same name, purely coincidentally, not related. I worked on an access/security software team at a major bank (about 350k employees internationally at the time), I found 3 bugs just by being me. Since even SSN/Tax-Id varied, there were several ways to match identity and I had conflicts in a couple of them with other employees. Last Name + last-4 of tax/ssn/national-id (for whatever country the employee was in) was one of them. I don't recall the other two right now, been about 15 years.
How so? Other than a funny coincidence, how would that ever come up anywhere in anything unless you both lived in a tiny community where everyone knows each other. I just don't understand how someone born on the same day as you having the same name was "irritating".