You appear to have missed something:
FCL-025
(c) Validity period
(1) The successful completion of the theoretical knowledge examinations will be valid:
(ii) for the issue of a commercial pilot licence, instrument rating (IR) or en route instrument rating (EIR), for a period of 36 months;
(iii) the periods in (i) and (ii) shall be counted from the day when the pilot successfully completes the theoretical knowledge examination, in accordance with (b)(2).
After 20 years you are way outside the box!