Hey Teralaser, how long do you realistically think it would take someone to determine if their business would be a success? 2 years? 3 years? 10 years? Also,

Hey Teralaser, how long do you realistically think it would take someone to determine if their business would be a success? 2 years? 3 years? 10 years? Also, if someone takes a multi-year break from school, how easy is it for them to just pick back up in a Ph.D. program? Is such a pause a deal breaker for most universities when considering an application to their programs?