Mr Blyth, you should remember one thing. A celibate island life fighting Turks is no particular guarantee of early maturity. Take a little crone-like advice, and don't rush your judgements.
In this quote, the speaker addresses Mr. Blyth, advising him not to assume that living an isolated, celibate life on an island fighting Turks will automatically lead to maturity. The message suggests that such experiences do not necessarily guarantee personal growth or maturity simply because of their difficulty or hardship.
The speaker further emphasizes the importance of patience and careful consideration in making decisions. They warn against rushing to judgment, implying that wisdom comes with time and thoughtful reflection rather than hurried actions or assumptions based on one's circumstances.