Is it normal to love something but be terrible at it?

So, I suck at blowjobs. No pun intended. Sadly I love to give them, but I'm terrible at them. It seems like when I start he's interested and then he gets bored and asks me to stop. Better yet, he wont even ask him, he taps my shoulder (the signal, I guess, for "stop, now. It's not getting anywhere and I'm bored")
Thats right
It's a "lazy" tap on the shoulder.
Thinking that this is just something you can read up on and automatically be good at, I start buying books.
Yet another fail.
Then I'm humiliated because he finds them.
As a final try, I ask him straight out- "What do you like?" Or I'll even ask him to show me.
He never gives me a full answer or even anything specific.
Is there a way to learn? Or should I just remove fellatio from my vocabulary?