"It's Only Hard Because You Make It Hard"

My happy charming Gerber-baby 13 month old really despises getting her hair washed. She goes from babbling, splashing, grinning cherub to demon-posessed-creature-with-superhuman-strength as soon as she figures out what I'm about to do. And so she screams, flails, and refuses to sit down in the large Ikea Samla bin that doubles as a bathtub in our desperately-needing-renovation 1880's home. To keep the bathroom from completely getting covered in water, I have to force her to sit and pin her down while I rinse her hair. It is not pretty. It is very noisy. And it is exhausting. 

After going through the ordeal tonight, I wrapped my traumatized cherub/demon in a towel and held her in front of the mirror to wave at the cute baby in it. "You know, it's only hard because you make it hard." I tried to explain to her that calmly sitting and allowing water to be poured down the back of her head would be quick and painless if she didn't fight it so much. It was good for her, it was going to get done either way, and she might even like it a bit if she just relaxed and got it over with. 

I don't think she's convinced.

But I thought of those words. "It's only hard because you make it hard." 
It's so clear to me, the torturer, that she's being ridiculous. 

But I wonder how I do this in my life. I got the nagging suspicion that I am just as guilty as she is. But I'm almost 40 years older. And should probably know better. 
How much easier would my life be if I didn't fight stuff? And what am I fighting that creates trauma and frustration? I'm not sure yet. But it's worth considering.