I've recommended YNAB to everyone who has asked me what I do for tracking my finances. I've been using it for 5 years now. I balked at the idea of paying for it but at the end of the free trial I was hooked, it just helped so much. All but one person I recommended to ended up integrating it in to their lives as well
The idea of surprise charges is completely unknown to me. It takes a little setup initially, but it gets you into checking your finances briefly every day which makes sure you are briefly checking whether you are going over your budget. You wake up in the morning with your transactions from the previous day and it does a fantastic job of matching them to your categories in your budget.
Unlike other systems you can't budget money that you don't have, so you have to break up your budgeting on a schedule of when you get your paychecks. You get into the habit of budgeting for your debts, bills, and things you are saving up for and you get to see how much you have left over for everything else in your life. It tracks average spending per category as well.
It's fantastic for tracking spending and debt but it's meant for your daily finances. It's not great at tracking stocks, 401ks, etc. But it's not meant for that and doesn't try to be