At 22, I had 2 year old (DD), was in my first year of my undergraduate degree - for which I had to travel a 4-hour-round-trip journey on a bus (well, three actually, considering we had to change them to get to where I went to uni), starting at 5.30 am, with my toddler in tow, before walking with and carrying her for half a mile, uphill, to her nursery, before backtracking, downhill, for a quarter of a mile to my part of the campus. Three days of the week. We often didn't get home again until late evening, too, depending on when my lectures and labs finished.
I had my own flat, rented from a friend's parents who had seen the way my parents were controlling me - and yes; I could have moved to a dorm in the uni with my daughter, but then when I'd finished the degree, we'd have had to move out again. Plus, my support network of friends were in our hometown.
I was also working as a ghost writer, just to bring enough money in to pay the rent/feed my daughter. I barely ate - just enough to keep going, really, because I couldn't afford otherwise. She was my priority. My student grant went on bus passes and nursery fees.
I was free from an abusive relationship, though. I didn't date. My son's father and I sort of just ended up together (we'd been friends from the age of 11), a few years later, but at that point, he would treat us to tickets for Disney films so that my daughter could be spoiled a little. I didn't drive, so we walked everywhere.
How grown up was I, though? At the time I thought "very"... now? I look back and see a terrified kid barely hanging on by her fingernails. I was exhausted (I used to get up at 3am so that I could prepare my notes for lectures and labs), malnourished, and missed my former work colleagues desperately (I'd worked in the field I studied for 3 years prior to starting the degree - which my employer at the time, a wonderful man who saw potential in me, pushed me into doing). I had no time for a social life, really, although my friends all claimed they didn't mind coming round to mine for coffee and cake (I made a lot of cake... it helped keep me sane, I think, that and the determination to cook my daughter's food from scratch every night). But I had a child. I was on my own. I had no choice but to behave like a grown up... whether I wanted to, or not.
My daughter's almost 21 now and, to a point, I envy her the freedom that she actually has. She's at uni in the town we live in, she lives at home, she can announce in the afternoon that she's meeting friends that night... and be able to go. Is she grown up? Not at all. Does she think she is? Oh, my goodness, yes.
I think we all do/did.