Absolutely this. My own company - as long as I believe I have a realistic chance of it working out then as long as I'm able to (ie as long as I can pay rent, etc).
If its not my company, then not at all. Even with equity, since equity is worthless (until its not).
I define "my company" as: I don't necessarily have to have had a part in coming up with the idea or have to have a fancy position like CEO/COO/CTO, but rather have physical ownership (equity; a minimum of 10%, anything less doesn't feel like really owning the company), my opinions matter (input) and the other founders recognise me as a founder and treat me as a founder (this includes being named as a founder on any documentation where doing so is relevant, eg, slide decks, angellist).