"Pop Wood", "Popped Wood" or "Popping Wood" refers being happy or joy-filled. One of the simple pleasures of youth was running through the forest (or any wooded area) and blissfully hopping over the logs, branches and sticks that were strewn about. That term reflects back to and is a remembrance of that purest of joy.
I pop wood everytime I get to visit with my grandkids.
A term that some European mothers (especially the Dutch) use in place of the word "erection" when teaching their children about the birds and the bees.