Maciej does not mean
Michael.
If you click on
Maciej it says "Polish form of
MATTHIAS" ... However, the Polish form of Matthias/Matthew is [also]
Mateusz. I actually had no idea that
Maciej and
Mateusz are related.
BUT definitely NOT
Michael.
In Polish
Michael is
Michal. Not sure about Lithuanian.

"We've begun to raise daughters more like sons... but few have the courage to raise our sons more like our daughters. -G. Steinem