Great question. I unfortunately don't have a mentor at my new job and it definitely hurt at first. However, I don't regret leaving as I've still learned a great deal independently, perhaps akin to a kid leaving home for the first time to go to university.
I do find mentorship to be invaluable and hope to have a mentor again in the future, though. I am forever grateful to my mentor from my previous job for the foundation he provided. He instilled good habits and philosophies in me that pleasantly surprised some of my new co-workers and we've even implemented some improvements based on what I learned from him.
#2 doesn't work if the company can't get anywhere close to #1.
With no work experience, I was hired as a junior dev with a $40k salary, which I gladly accepted. A senior dev mentored me throughout the year and it was fantastic.
Coming up on my 1-year anniversary with the company, I was thoroughly enjoying my job, the people, and the culture. I was hoping to get a raise up to at least $60k, though, since I was significantly more valuable to the company than I was when I first joined. They offered me $50k.
I started applying for other jobs and got an offer for $90k and I accepted it. I still talk with my mentor from my previous job. He's pissed that his company won't pay enough to keep the developers he mentors.
I do find mentorship to be invaluable and hope to have a mentor again in the future, though. I am forever grateful to my mentor from my previous job for the foundation he provided. He instilled good habits and philosophies in me that pleasantly surprised some of my new co-workers and we've even implemented some improvements based on what I learned from him.