Are the ablution and the prayer of a person who did a mistake unknowingly in his ablution for two years valid?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

If the mistake invalidates ablution, like leaving one of the pillars of ablution, then both the ablution and prayer are invalid, and it is an obligation to make up the prayers which were performed with that ablution. That is because ablution is not valid if one of its pillar is not fulfilled, and the prayer is not valid if the condition of being pure is not met. It is confirmed that the Prophet saw a person praying and a part of his heel as big as the coin of a Dirham was not touched by water, so he ordered him to renew his ablution and repeat the prayer. [Abu Daawood and Ibn Maajah]

However, if the mistake does not invalidate ablution, like leaving one of the recommended acts of ablution, then both the ablution and the prayer are valid.

Allaah Knows best.