Is the following a good philosophy of Life?

Investing time in developing good habits and skills early in life will be the best investment you will ever make.

No, in my view, it's not a good philosophy.

Perhaps, if you were to elaborate, it could be worth something.

Necessity is conditional. Nothing is necessary unless it is to achieve an aim, and it is the only way to achieve the aim. Even breathing isn't necessary if one doesn't mind dying. However, if one wishes to know what it's like to get high, it is necessary to experiment with the drug that one wishes to know about. 

No, it's not a good philosophy.  Life would be very depleted if people only did what was strictly necessary. There would be no music, no art, no literature, no movies, no sport and nothing else which is pleasant but non essential.

Another problem is that sort of philosophy can easily be corrupted into a selfish, individualistic attitude which denies collective responsibility.Imagine a child is hit by a car, and a group of people gather round. Under your philosophy, which of those people would help the child? Each of them could say 'it is not absolutely necessary for me to help, because there are other people here who could help instead'. The only way to break that deadlock is to say 'it may not be absolutely necessary for me, as an individual, to help; however it is absolutely necessary for us, as a group, to help and so I have a shared responsibility to act as part of the group'