Start walking towards the right after the dialogue with Watts. You'll eventually see a break in the fence by the road. Enter through it and watch Watts be an idiot.
Inside the closure, keep moving to the right and go up once you see the barn house. You'll find Johnny and River on horses. Speak to the unimportant person in front of them.
When you get on the horse, gallop all the way to the left and you'll find a fork in the road with two large trees on the north and west side as well as a small tree on the east side beside a pond. You'll get a random memory link here.
Stand on the path just above the pond near those trees and wait for River and Johnny to pass through you on their horses. You'll get a memory link from each of them.
Sorry, but you're gonna have to help Dr. Watts. Chase after him and press enter once you're close enough to collide. Watts will fly off of the horse.
Head back to the barn on the right side of the enclosure. Watts will be standing there in front of a handbag. Place the memory links in the handbag and prepare it.
First press the blue, yellow and purple button on the left side of the puzzle, then press the diagonal button to solve the puzzle and move on to the next memory.