My problem is I always feel like I'm going to need more cash.
Right now we have ~$60k in liquid assets, but there is always a demon inside telling me we need more on-hand.
My wife wants a new car, better save so we keep the same amount of cash on-hand.
We want to have a kid soon, we're going to have a lot of expenses to fill the baby room.
We want to have a kid soon, better start saving for his/her college-fund.
It's a double-edged sword, because while having liquid assets are useful at times - having cash just sitting in a shit interest bank account not accruing any real interest (Retirement accounts) is not useful.
Go talk to a banker. Not the teller at the front of the long line. But a real banker (the people sitting in the offices or cubicles scattered around the bank). Seriously, go do it this week.
Set up a plan where you are pre-approved for a loan in an emergency. Use your investments as collateral. Note, this isn't selling your investments at a bad time (such as selling when the market is down or having a big tax bill when you sell to pay off your emergency). This is keeping your investments invested and getting a loan from the bank in the off chance that you have a big emergency. Bankers love this setup: they are potentially loaning money to someone with $60k+ saved (i.e. you are very unlikely to default) and the interest rates are therefore near zero.
In the worst case scenario, you have to take out that loan and pay a few hundred dollars of interest to the bank. Compare that to the $7000 you just lost by not having that $60,000 invested in a S&P tracking fund last year. It is time to have your cake AND eat it.
Very few emergencies are more than $3000 anyways. A new furnace: $2000ish, a new heat pump: $3000ish, a new engine or transmission: $2000ish, a big medical bill: $3000ish (or you have the wrong insurance). The only real reason to have more than about $3000 in emergency funds is for a lost job. And you already have unemployment insurance that covers you in that situation. You are just saving way too much cash for virtually no justifiable reason.
The only justifiable reason to have that much cash is that you have a specific plan for that $60k, such as buying a big ticket item or waiting for prices to go down for a specific investment (and even then that is often a bad reason because timing the market is a losing game).