According to the author of the book of Judges, an angel told a woman she would have a baby boy and she should not drink wine or eat certain foods because her son would be special to God from before he was born until he died. This means the boy would be dedicated to God and have important things to do.
Judges 13:7: But he said unto me, Behold, thou shalt conceive, and bear a son; and now drink no wine nor strong drink, neither eat any unclean [thing]: for the child shall be a Nazarite to God from the womb to the day of his death.
This verse indicates that a Nazarite vow is a choice anyone can make, which contradicts Judges 13:7 where the lifestyle is imposed on Samson from birth by divine command.
Numbers 6:2-3: Speak unto the children of Israel, and say unto them, When either man or woman shall separate [themselves] to vow a vow of a Nazarite, to separate [themselves] unto the LORD: [to separate...: or, to make themselves Nazarites]