The thing about working for a start-up or a small company is that you become emotionally attached to the company.
You develop a sense of ownership for it — even if it’s not yours — because you get to experience the company in its entirety. You observe the good (and bad) side of its operations, you listen to spoken (and unspoken) conversations, and if others don’t see you as a threat (that’s the good thing about being underestimated), you can float around and talk to everyone as a neutral party.
In time, you become proud of the company, you worry about its future, and you feel even more motivated to do more to help it. You find a meaning in doing your work because in a small company, whatever you do, matters.
This is one of the perks of working for a start-up or a small company.