I agree with this. I know quite a number of people who had a girl or two, and then had a boy, and they said if they had had the boy first, they'd never have had another child. The girls were an absolute dream compared to the boy. Not perfect behaviour all the time, but very good behaviour most of the time. The boy is/was disruptive, screechy, ranty, prone to throwing tantrums, and they seem to stay with the demanding 'toddler like' behaviour til they're about 6 or 7. Unlike the girls who grow out of it by 3.
Judging by the bother some parents have had with boys (especially moreso if they're a second or third child,) I am really glad I had girls! They have had their moments, but compared to the behaviour of some boys I know, and the stress they have put their parents under, mine are absolute Angels.
I saw a woman the other day with a little girl - around 8 years old, and a boy who can't have been more than 18 months younger who was being an absolute demon. Screaming and shouting and hitting his mum, and throwing himself on the floor, and throwing stuff around. The little girl was on a bike (without stabilisers,) and she seemed quite advanced and sensible for around 8, chattering to the swans, and tootling along on her bike...
The boy (who was at LEAST 6 and a half - or maybe even 7,) was like a screechy 2 year old toddler. Dreadful behaviour. The mum was frazzled and very red faced with anger from him. I felt sorry for the girl to be honest, she was being mostly ignored, because her mum was too busy trying to placate her brother.
I don't know why it is, but yes I agree that girls are usually MUCH easier to look after, than boys, especially when they're. say, under 10. The girls are a bit more difficult during the teen years, and are meaner to one another than boys are, but then when the girls are grown, they tend to be a bit more loyal than boys (regarding staying in touch, coming around to see you, and being in your life more.) Not ALL of them, but moreso than not IYSWIM.
@Yankeecan Sorry, no advice, expect roll with the punches. You're not alone. As a number of posters have said, boys can be very difficult and are more likely to be hard work than girls. (Again, not ALWAYS, but moreso than not!)
disclaimer All of the above based on my own experience and that of quite a number of people I know/have known.