My childhood, in general. Although I was not a good child by any means, and it's truly mortifying what a bully/wretch/push-over I was. I was very horrible to several people when I was little. (SAM). He has received counseling for his psychological scars, and has forgiven me for my offences. (I think.)
One of the awesome things we did when we were younger was jumping out of this really cool, big, dead apple tree. It wasn't that tall, but it felt miles high every time we teetered on the precipice and had to get the nerve to jump. We often had to encourage Juli with gentle shoves. :-)
So that's what I would go back to--jumping out of that apple tree.
P.S. Sam did not actually get counseling. Maybe he should.