Don't put all your trust in a mentor on achieving your goals in life, it is because your mentor and you had different situation that has also a different solution, so i think we need to have faith in our own self capacity to pursue our dreams not just trusting our future to others or to mentors hand.
Having a mentor is not a bad thing, the necessity of it is just to get a good guidance in what ever you decide to pursue (career or whatever), most of the time and for some people too, mentors can be a source of hope for them in which they draw their zeal from and become motivated. Some people actually needs to pushed before they can stomp into action and that's the purpose that mentors serve for some persons.
Yes, having mentor that can help person with guidance will help to get good at what you do faster, but I believe mentor is not critical for success is one has clear goal and is willing to start over after each failure.
Sure, mentorship is good but can never guarantee success, it only helps your guide faster. But your success depends on many factors, which are not limited to you, the resources at hand and your luck/fate/grace.
I know many would query the last but I tell you, it's a fact whether you like it or not. This explains why some people do it better but still fail despite all the commitment and hard work, and even the huge wealth of resources invested. But some people will do a little and prosper in the same field/business easily.