[jimmySixDOF]

It's better to say: The biggest investment is your time.

Sweat = Equity

[jlbnjmn]

Sweat * leverage = equity.

Time used wisely is an investment, but time used poorly is an expense.

Being able to tell the difference is key.

[bennyelv]

That’s only a practical way to think about it if you have enough other income to cover your expenditure. Equity doesn’t pay your rent.