Most is defined by the attributes you apply to it. "Most of your time" would imply more than half, "the most time" implies more than the rest in your stated set. Your time implies your total time, where the most time implies more than the rest. I think "most" leads to a great deal of ambiguity.
What does the word "most" mean? - English Language & Usage Stack Exchange
Most is what is called a determiner. A determiner is "a word, such as a number, article, personal pronoun, that determines (limits) the meaning of a noun phrase." Some determiners can only be used with either a countable noun or an uncountable noun, while others, like most, can be used with both countable and uncountable nouns. Uncountable nouns usually take a singular verb. So, in your ...
A thing I have never had the time to look more closely into. But I find both variants: What I love most is ... or What I love the most is ... I think the more common form is 'the most', and I ...