nir·va·na (n�r-v�n, nr-)
n.

1. often Nirvana
1. Buddhism. The ineffable ultimate in which one has attained disinterested wisdom and compassion.
2. Hinduism. Emancipation from ignorance and the extinction of all attachment.
2. An ideal condition of rest, harmony, stability, or joy.

I think you've also misinterpretted this guy. At least from what I can tell. I think he just means he feels very peaceful when in nature. Is this something foreign to you? It's definitely not to me.