One of Martin Bjergegaard's key points to success in Winning without losing with a startup is to have a strong cofounder and not try and do it by yourself.
There's an old African proverb - If you want up go fast, go alone. If you want to go far, go together.
Humans are social animals. We are heavily influenced by the people we surround ourselves with. Good luck with being happy if you surround yourself with unhappy people. Good luck with being successful if you don't surround yourself with successful people. Good luck thinking positively if you surround yourself with negative people.
Do you have any friends where they're a great time and you always enjoy spending time with them but every time you see them, it's kinda just the same experience replayed again and again?
Jim Rohn's talk on the law of averages (you are the average of the 5 people you spend the most time with) has been used in multiple motivational and self development talks, books, seminars and trainings etc.
It's really key you only let people who are positive influences in your life.
Noel introduced me to the concept of levels of a relationships that's described in this New York Times Article, the basic summary is that there's three levels, first, economic exchange, second, companionship and third, personal growth.
I now only look for relationships in all aspects of my life - professional, platonic and romantic, that hit all three levels.
It's a really tough shift as it means you have to stop spending time with a lot of people you've known and loved for a long time. These people probably do a great job on the first two levels.
Really for me, what it came down to was becoming more purpose driven and realizing that to achieve my purpose and goals, I needed to step up, keep growing and keep learning. One of the best ways to do that was to surround myself with people who could help me learn, who were purpose driven, who would inspire me, push me, motivate me... help me become better.
I'm not going to lie, making a conscious choice to stop spending much time with a lot of my mates was tough. It was necessary though. You can't bring people with you, you can only invite them to join.