When it comes to alcohol consumption what is the meaning of "your limit"?

I'm not referring to how many drinks/units your limit is, as obviously that is contextual on the person, but where on the drunk spectrum is being referred to when people talk about "know your limits"?

My partner says the limit means needing assistance, so if you come home stumbling, slurring words and lack a lot of function you haven't reached your limit so long as someone doesn't have to carry you home and put you to bed. I disagree but I cannot really articulate where I think the limit is, but it is somewhere before that.