Yes it is good to turn a hobby into a second career. Let me explain with an example. If a person is a software engineer and his hobby is photography, he should continue to work as a software engineer which is a stable position with regular income and do photo shooting during week ends to earn extra money and that way he could enjoy his passion as well . This will eventually help him to hold an own job once he retires . In fact, he does not have to search for jobs at the age of 65, instead the experience he gained through his second career so far would help to earn money and keeps his life engaging! That’s why it’s always good to have a hobby and upgrade it as necessary to meet the day today standards of life. To summarize , it is important to have hobbies and convert it into part time career which in turn would become full time as we age to keep ourselves fully engaged and active:)