I'm currently the only founder for my startup and have a CS/Engineering background. I find that almost everybody I talk to seem to think its crazy or impossibl

I'm currently the only founder for my startup and have a CS/Engineering background. I find that almost everybody I talk to seem to think its crazy or impossible for a single person startup to succeed. I wonder what the whole deal is about: - is it because they feel its too much work for one person? - they assume that one person cannot be motivated/determined enough to make a startup successful? - or is it just based on the fact that most of the successful startup were stared by 2-3 person teams.. I'm curious to hear your thoughts on this guys..