If you can sit at the computer all day then yes possibly. Buying and selling, trades, services or jobs, and even mining if you can afford the hardware
But that would be stressful. Just 8 hours of working in front of a computer makes your back and your eyes tear. Working for bitcoin for a little time would be great specially if you are just doing trading.
Yes, setting at the computer all the day is pretty impossible in the long term, even for people who work full time online. Trading could be profitable but you have to make good experience about it and start with big budget usually.