Our sages compare a Nazir Shimshon, meaning like the ancient hero and judge Samson (Judges ch 13-16), to a Nazir Olam or permanent Nazir. A Nazir like Samson can never cut his hair but can touch dead bodies, as Samson himself fought and killed Philistines to defend his people.
A permanent Nazir is allowed to cut his hair when it become a burden, and then bring offerings at the Temple and resume his vow of Nazirut. Our sages debate if the eligibility to lighten the hair applies after 30 days or only after an entire year.
Even if he must wait a year to cut his hair, this “permanent” Nazir does not seem any different than someone who vows a regular Nazirut for a full year, then makes another year long vow after he concludes the first one. So why have a separate category for a permanent Nazir?
If you want to make a specific change for the rest of your life, this takes a much greater level of commitment than trying it out for a shorter period of time. Committing to a set of higher standards on a permanent basis can be daunting. Depending on where you are holding in life, it may be more appropriate to try out something new for just a week or a month.
Red Pill Rabbi 