The 2N2222 is an old workhorse. But......
The earliest datasheet I can remember seeing for it dated way back to the mid-sixties, perhaps1964. It was part of a family of NPN transistors that included 2N2217, 2N2218, 2N2219, 2N2221 and 2N2222.
It's kind of sobering to think that there are '2222 transistors on the Pioneer probes that have now exited the Solar System.
As common as these devices have become though, as trustworthy as their characteristics have become over the course of time, now and then, here and there, some devices can come to the loading dock that do not measure up (pun intended).
These two superimposed curve tracer images, admittedly from a good many years ago, will illustrate the point.
As confident as we may feel with our so-called garden variety parts, every so often, at least now and then, even today, it may be a good idea to just check 'em out. It had not occurred to me back when I took these images, but the transistor on the left just might have been a counterfeit.
In retrospect, I had some reasons to be suspicious of that, but I guess now I'll never know for sure.