You're no longer new, and everyone assumes you ‘don't need help’ any more. You're ‘on your own’ now, it's ‘sink or swim’ time.
In a way they're right - mentoring isn't ‘remedial', it isn't about ‘fixing’ or ‘helping’ in the sense that you can't ‘do it yourself’. But successful people don't feel they have to ‘go it alone’ - they identify resources in people as well as in print or online, and use them to maximise their potential. Research has found that the most effective people may have four or five different mentors for different areas of their professional and personal lives.
It's simply the case that your mentoring needs have evolved in line with increased responsibility. You may have new duties, taken on new roles, been promoted. It's more about the synergy that two (or more) people can create between them to generate solutions, strategies and action plans, to build on success.
Mentoring is important as it provides individuals with role models and may be a means of providing information about career and training opportunities (internal and external). Importantly, the mentor might provide the inspiration to take these opportunities up. Mentoring also widens the support network, provides motivation and can improve confidence.
Developmental mentoring is just that - an experienced mentor helps you to develop your strengths and potential, to identify your changing needs, values and aspirations, and what's most important to you. They work with you to plan your professional development, and your next career steps. Personal development planning is now encouraged in most universities, and is beginning to apply to staff as well as students.