i still cant lift a 17.5kg bicep curls...reach my plateau for sometimes ..chest press also ..

My question is how do you all know you all hit your max weight that you can lift?

Let say you start lifting 2kg from the start of the year. So if you increase 2kg every week, by the year end you will be lifting 52 x 2kg = 104 kg, and in 2 years you will be lifting 208kg if you increase 2kg every week  .

This may sound crazy or like impossible, so how do you all know you all hit ur max lifting weight?

Cause right now lifting dumbbells on flat bench at 35kg I already can feel the "pain". 

Thanks in advance to all sifu/master here.