Research is very labor intensive. It's easy to reach a point where the lack of time is a bigger obstacle to pursuing your ideas than the cost of pursuing them. Which is why you need to apply for grants to hire people to do your work.

At 25, you are likely pursuing somebody else's ideas, because you have not proven yourself yet. At 35, you should be pursuing your own ideas, but it often gets delayed to 45, because taxpayers are stingy with their money.