You don't need a co-founder
I've been thinking about this for a while now. I might not be right. To be honest, my experience is limited.
Conventional wisdom is that you should always have a co-founder. This person fills in for your weaknesses (and tells you where those weaknesses are), inspires you when times are rough, gives you a sounding board to bounce things off, and generally dispell the lonliness of founding a company.
However, if you look at the traits one at a time, perhaps a co-founder is less necessary than you think.
1. Weaknesses can be filled by freelancers, consultants, and contractors at the beginning, employees later.
2. A spouse or honest friend can point out weaknesses, if you're honest enough with yourself to listen.
3. When times are rough, you can look to your existing customers to inspire you to continue. You are making something valuable for them.
4. You can bounce ideas off your community.
5. You are never lonely when you have customers that you talk to and a community to echo inspiration.
So you don't need a co-founder if you have customers and a community. In the old days, it took a long time to get customers and a community. Today, it's possible to do almmost instantly. With holdist, I had people using the product within 4 hours of starting development. Not a lot of users, but enough to keep me inspired.
We'll see how it turns out.