I invest about 60-80% of my income. There are a variety of reasons but here are some:

1. Spending money doesn't seem to make me much happier. Buying stuff is certainly fun, but the enjoyment of owning a new thing wears off in a few weeks. Also, some things have carrying costs, they make moving more difficult etc.

2. I'm in my 20s, and I'm worried about possible trends toward large scale structural unemployment and declining median income per worker in developed countries. If these trends do continue, owning a fair amount of capital will be vital if you want to be financially secure.

3. I also get some pride from watching the numbers roll upwards on my accounts. It reminds me of how people who have lost weight often say, "no food tastes as good as being thin feels."

People really do seem to have different utility functions/discount rates etc. YMMV, but I like the feeling of having money more than I like buying/owning stuff.