Is spook proofing possible?

A friend suggested to teach Ramere to spook in place rather than jumping to the side.
(Too good to be true?)
Now Ramere is usually great.
No reaction to flapping tarps, trucks (and I mean TRUCKS) flying by,
or dogs barking while charging us.
Nope, he spooks at ...rocks?...logs?
We were walking a flat walk, nothing to get excited about.
The horse in front of us was calm.
We had trotted for about 3 miles prior so he wasn't "hot to go."
The trail was flat and boring. He jumped to the side without a warning.
Then he was fine. His spooks are always over quickly.
He will even spook while we're going at speed.
Then as suddenly, he'll continue to trot along.

I would also like to know as I also have a big 4 yo arab gelding that is very calm, when he spooks on the property where he is kept he spooks in place. He's a very fast learner, isn't afraid of things and loves to be with people. I've had 30 straight training days put on him and the trainer says he's "well broke" and is ok to take out on the trails alone. So I take him out alone and he spooks big time, spooking off to the side and while I'm trying to hold on for dear life, he spooks again and dumps me. Then he runs away at a full gallop. He doesn't do this at home and I have never seen him this afraid. How do I train him for this? Like Nina says, my gelding also shies at sticks and rocks. But when he spooked and dumped me, it was a couple of birds that were not even near him. Does he need to be with other horses for a while? I don't have a lot of people to ride with. They're once a month riders at best and if I'm ever to get out and ride I have to do it alone. I was fortunate that where we were that day was gaited. He was waiting for me at the gate. Then the fight began when I tried to put him into the trailer. He got hurt in the trailer and when other people tried to help me, he came out with both back feet flying in all directions bucking and kicking full force. He scraped his leg on both sides and ended up with a gash on his nose which now, almost 3 weeks later, I am still trying to doctor. Was it too soon to be alone? Anyone, can you give me some advice? Thanks.