HPV is the most common sexually transmitted infection.HPV is so common that nearly all sexually active men and women get it at some point in their lives.
Again as already said condoms can reduce the risk of contracting HPV but uncovered areas can still spread the infection.
Most people don't know they have and live with HPV symptom less their whole lives, the main symptom as far as I know is genital warts, and abnormal smears can show HPV.
IF I were u i wouldn't worry, if u had abnormal cells 20 yrs ago you've had a strain of the virus for a long time so I wouldn't stress unnecessarily, just my opinion x
Best of luck with the removal of cells, been there too xx