When tech journalist Dan Lyons was laid off from his position at Newsweek after 25 years, he decided he would try working for the startups he used to write about. His new book, Disrupted: My Misadventure in the Start-Up Bubble , chronicles the two years he spent at marketing software startup HubSpot in Boston. Lyons recently talked about the surprises he encountered in the startup world on the Knowledge at Wharton show   on Wharton Business Radio, which airs on SiriusXM channel 111 .  An edited transcript of the conversation follows. Knowledge at Wharton: Explain how you ended up going to work for HubSpot. Dan Lyons: I was working at Newsweek and got laid off and looked around and saw that it wasn’t just my company that was struggling; the entire industry I was in was struggling. I thought I should start a new career, even though I was 51 at the time. I thought, I can start over. I thought marketing would make sense.…