SAD

1. A friend that knew you before you started your own thing.
Perhaps no voice matters more than the one that knew you before you had a startup. They knew you when all this was just a dream, or when you didn’t even know what a startup was. They can speak to your roots and ground you when you get lost in the startup haze.

For instance, when I go back home to the East Coast, my friends ask me about everything except tech and business. They tell me how impressed they are but remind me that I need to slow down, to live the life I want, doing what I love. No entrepreneur should lose sight of that.

2. A person with your similar skill set at your point of learning.
Having regular coffee dates or Skype chats with people who are in your similar phase of growth can lead to valuable relationships. I have a group like this, and we push each other and question each other’s decisions. We have been there when things fell through and when our big days happened.

There is a confidence that can come with camaraderie like that. We understand what each of us is going through.

Related: The Art and Craft of Listening to Your Critics

3. A colleague you don’t love working with.
One of the biggest challenges that face any entrepreneur is justifying what you want to do and why it’s going to disrupt the status quo — whether it be to investors, future co-founders, team members, the press or others. It helps if you’re good at talking to just about anyone. Fine tune your ability to take feedback and get good at turning it into positive results. There is no quicker way to do this than to push forward with a relationship that isn’t particularly enjoyable or easy at first.

4. A person with the exact opposite skill set than yours.
Seek out mentors who are most unlike yourself. For me it’s been coffees with product managers, and tech leads. I’ve met with chief operating officers and have standing chats with our office manager. Do I know much about any of that? Not really. Do I know more now than I did before I met with them? Sure as heck I do.

Having these types of mentors and encounters has motivated me to take classes in coding and financials, and it’s humbling to see just how much you don’t know. Life-long learning is critical to success in business, and particularly to those who have bought into an industry founded on innovation.

5. A friend who always knew you’d be an entrepreneur.
Meet often with someone who knows you as “your entrepreneurial self” and not in any other way. He or she is likely the one to say “you got this” and “this is what you do” — even when you’re doubting it yourself. That person can’t imagine you ever taking the safe option or quitting. He or she would never tell you it’s OK if you haven’t given something your best effort, and will cheer every one of your accomplishments.