I like to do 5 year challenges/tracking. I track our financials once/year and load the numbers, and project "5 year goals" in the future to see what I think we'll be at, so if I don't hit it or it looks like we're not, I tighten up, if we exceed it I get really excited! We haven't paid off the house as interest rate is so low after re-financing, which was difficult to switch my mindset, as we were on the rate before refi to pay it off in around 7 years from now. So I focus on the 5 year projects, and the pessimist in my always says "a crash is coming", so I try to take 30% or so off of our NW just to keep things in perspective. We hit $1M NW a few years ago, then $1M invested, then $1M retirement accounts, then I hit $1M investments w/o DW in the equation. We have 3 boys and 3 529 accounts and are doing pretty well there, so I just like to keep 5 year goals and track them. I get the people who've said that hitting $1M doesn't feel like much, but honestly I enjoy it every time I creep over that milestone!
Next milestone for me is to become a TSP Millionaire, then have DW become a 401k Millionaire, get the boys through college w/minimal debt, pay off the house, etc.
Since you put most of your eggs in the paying off the house basket, just shift gears towards investment goals, hitting certain net worths. If money doesn't interest you now, then pick up a hobby.
I don't brag about NW outside of this forum, and to DW, but through conversations in work, older employees who thought they were money savvy quickly learned that they are not even close to my knowledge (and really I'm not good at all - I subscribe to the low cost index funds and set it and forget it), but talking to these people and giving them this basic advice makes me feel like some kind of a genius around them when I give them very basic advice like "save more and spend less", and "you're paying 1.5% for your financial advisor to not even match the S&P500, and I'm paying $0 in Fidelity no-cost index funds" and stuff like that.
That gets me excited when I get a weekly call from a co-worker who needs guidance about money and retirement!
For a 2nd home, that used to be a dream of mine, having a vacation home, until I bought a home and hated the stress of it. We had a rental condo b/c we moved in 2008 and had to weather the storm for a bit, and rented for 3 years, and the day we sold was a huge weight off my shoulders. So you can do that if it doesn't stress you out, but personally I could gain or lose $15k/day on a normal day in the market and it's easy for me to justify, but getting a call for a $200 repair would keep me up at night... So to each their own in the real estate department, I guess you have to have a certain mindset to own property.
I would aim for smaller goals, having a 1 year goal or really a 5 year goal is good for me, and even before I hit that goal, I'm setting out other goals, so sort of like a CD ladder for goals :) If you keep up w/mini goals it will help keep you motivated, keep you excited about hitting them, tighten you up when you slip up, etc.