Now is your chance.
In between my Ph.D. and first post-doctoral stint, I took three months off. Bicycle touring, surfing lessons, and visiting friends across the country. It was one of the best things I've ever done (even considering the credit card debt).
So whatever counts as an adventure for you, go and do it now. Unstructured time off is hard to come by in the sciences, except for the very few elite scientists and engineers who can manage their career on a 40 hour work week. I'm now in year 5 of my post-doctoral work, and I don't see another vacation like that any time soon.