Yes. This is so true. While I'd never trade my couch or hammock for an office again - my boyfriend often accuses me of 'not being here' - it's easy to become a workaholic - because you only have you to depend on.
When you work for you, there's no guaranteed paycheck - sure you are the 'master' of your own time, but rarely is sleeping all day even an option. If you don't put out the work to find work - you don't get paid.

It's easy to become obsessive - often out of necessity to make rent - and work 12 or 14 hour days. Finding that balance is essential - as @Britt.the.ish said.

This isn't to discourage anyone from quitting their day job! It's just to set a realistic expectation. The beauty of working for you is that yes, the sky is the limit, no one is capping your salary, you choose your own hours, can work from anywhere (depending on the type of freelance work you do)...but there are tradeoffs.

Very few people quit their day jobs and poof ! Have enough to travel the word while generating enough income to sustain continued travel. It doesn't happen over night. That's not to say, one couldn't immediately move to another country with a lower cost of living, and begin freelancing (that was my 20's!) - but still different than instantly traveling the world within your first few months of being self employed.

Only you know your situation, of course. Whatever you decide, good luck !