I got a good idea of what it feels like to be rich by going to a third world country. Even though I'm just barely scraping in at average in Australia, I was seriously freaking loaded by an order of magnitude compared to most people in Ghana and could afford to take the nicest cars (taxis) buy beer regularly and eat at "real" restaurants rather than roadside vendors. I was able to buy 5 or 10 dollar mobile recharge cards whilst most of the population purchased their recharges in 50 cent increments from street vendors.
I'm sad to say that my biggest reaction was frustration. Everyone I met was trying to get my money somehow. It seemed like every conversation would turn into some sort of scam opportunity or even just wanting to get my help somehow.
I thought "I can't help you people! I'm just normal, I don't have that much money!". It wasn't until I was actually on the plane home that I realised that I'd just experienced being rich. It seems as though it's all relative - that the "rich folks" don't see themselves as rich because when you're rich, you just get bigger expenses.
Of course your standard of living improves, but it must be hard to ever feel so rich that you're happy just giving money away to everyone who asks (and I'm sure that you get asked a LOT).