At one of my gyms there is a poster that reads: YOU ARE ONLY AS GOOD AS THE PERON YOU TRAIN WITH. I think there is a bit of truth in that message.
If you believe yourself to be one of the "Undisciplined ones", then it can help you to initiate friendships with people who show good discipline, or hire a trainer. More importantly if you look for someone to simply work out with---make sure you buddy up with a person who is motivated.
Teaming up with a chronic whiner or a negative realist,only means you will spend more energy assisting them. Choose to be with someone who has an attitude that you admire. Choose to be with someone who has the character of discipline equal or more than you.