I was exposed to GH 25 years ago, never had the initial outbreak, and then tested positive 20 years ago, but have still never had an outbreak on or near my genitals. Is this normal? Can someone have the virus and never have symptoms?
Yes, that's possible. It's also possible that your test result is a false positive. How were you tested? If by blood, was it for IgG or IgM antibodies to herpes? What were your index values for HSV1 and HSV2?
False positives are rare. False negatives are common.
Not exactly true. The IgM test is unreliable and it is not unusual for it to produce false positives, so the test is not advised for herpes. Low positives on the HSV2 IgG test, especially with pre-existing HSV1 (oral or elsewhere, symptomatic or not) and no confirmed genital outbreak, can also be false (the UoW western blot can help to confirm, but that test is pricey and not readily available). And those are modern blood tests, not ones from 20 years ago.
False negatives are also possible if blood testing is done too soon, and for some people with HSV1, depending on the test kit.