I would go from feeling rich one month because a freelance client had paid a bill, to not having a cent a month later.
There were times when it felt like I was running a pyramid scheme on myself. Needing to use money from a previous job to buy computer hardware to sell to the next client.
In retrospect, I was also too proud to ask for help. I let things get way out of control before my mother ended up taking out a personal loan to bail me out at one point. If I had asked for help earlier it would have been a cheaper problem to solve.
It took years to shed some of the residual behaviours, even after I started earning decent money. Despite having savings and reliable income I would still let bills run until they were overdue.
These days I'm a lot more proactive about personal finances and good money management, but it's hard to tell how much of that is just maturity, and how much is the fact that I no longer have problems with unstable income.