Everybody Makes Mistakes

That is why they are built into the halachic system. Saying "I am not perfect and make mistakes" is saying "I am not G-d". Nothing to be ashamed of...

Two shylos that I had today:

I said the wrong day of korbanos during mussaf.

Halacha - No need to repeat mussaf.

Someone else told me that he accidentally said the Shalosh Regalim shmone esrei at mincha [today is chol hamoed:-)].

Verdict - He must repeat mincha and say the weekday shmone esrei with yaale vi-yavo.