Lazy or just lacking that extra 24 hours?

I know I am biased in this matter, but I still can't understand why it seems to be so incredibly difficult for people to understand what it means when someone is, as I call it, solo parent. (I don't know if there is a real English word for someone who is 100% single parent. In Finnish we are called "totally single parents" (totaaliyksinhuoltaja or totaaliyhäri) so I use "solo parent" as I think it should be figurative enough.)
Admittedly even people with shared custody call themselves single parents (well, in English it's more accurate, but in Finnish "yksinhuoltaja" (single parent) basically refers to someone who has sole custody and sole responsibility - or it should). What is even worse I have met people who call themselves "single parent" (remember that I use the word just because it translates like that) even they are only "weekend parent" with shared custody.

That confusion with terms apparently makes it really impossible for some, many, people to understand, or even try to understand, how life is when you are the only parent, or both parents in one.
Admittedly it's not that much different when it comes to basics, but the major, major difference lays in time: totaaliyhäri has only 24 hours a day to take care of things that are usually taken care of by two people who have 24 hours a day. And we do not have free weekends, ever, like most shared custody parents - or even single parents if meetings work.
What bugs me in this is that people seem to consider me lazy because I simply do not have time or energy for everything - even I have on average 8 hours of "free time" (which translates to Tiny's daycare day being 8 hours/ day on average) every weekday! I wonder has it ever passed their mind that being two people 24/7 is rather exhausting in the long run... so, when Tiny goes to daycare I walk home, eat breakfast, drink coffee (this takes about 2-3 hours depending do I go to grocery store when I walk home). Wash laundry. Study. Hang laundry. Eat. Study. And all the sudden it's afternoon and I need to go and pick up Tiny. So, in real world I have 4-5 hours tops to actually study.

I'm such a lazy ass b**tard. ^^