Over the years, I've often heard things about things that "save time" in development. For many years, I was gun-shy of IDEs. Too often they break down, and the entire thing has to be reset and reconfigured from nothing. It made the cost out-weight the benefits. After a few more years passed, IDEs got better, and when somebody introduced me to IntelliJ, I was finally convinced that IDEs could actually save me time overall, not cost me, normally at the most inopportune moment.
So now we have IDEs that don't suck. Take a simple thing like method lookup. What's the time difference between hitting Command-B in IntelliJ, or having to do Ctrl-H, change the tab, and type it in in Eclipse (I'm sure there's a better way in Eclipse, there always is, but it normally non-obvious). It amounts to a few seconds at most. So, there's not really a significant difference right? In time, this is perhaps true, and some might argue that a few seconds here and there can add up, and I might go into that later. For me, the real issue is not time at all, it's space. Space in your brain.
A brain is like a CPU in some ways, and like a CPU it has a cache (at least this seems like a good analogy to me), you have multiple levels, at least L1 and L2, maybe L3. L1 caches are small and very fast. They handle what's the immediate focus of attention in your brain right now. Jumping through the code, tracing back a problem, going up the code path. When needing to search, instead of jumping directly to the caller, you have to go through a set of operations. This results in only a small time difference, but, it's like having to put three or four operations in your L1 cache instead of none. Hitting Ctrl-B is a zero effort operation. It's just like an op-code - Ctrl-B does this, that's what I need. Opening the search dialog is a zero effort operation. Remembering to switch the tab, not a zero effort operation, copy/pasting the right string in, not a zero effort operation, checking to make sure it's including the right files, similar, and if it's a big project, watching the search run, and then popping up an error dialog, not zero effort.
Another four things are now put into focused attention, significantly depleting what's there. Two seconds of time has busted through maybe 20% or more of a brain's L1 cache (I think I read somewhere that the average human can only concentrate on no more than four to six things at once). That two seconds can turn into two hours as the most important thing that was being held on to at the top of the stack in your brain which was in "L1" gets lost down into L2 or worse. We fix the immediate problem, but forget why. The local manifestation is gone perhaps, but the bigger issue is forgotten, and still very present.
Two seconds, concentration was diminished, which caused two hours of lost time. This is one way how every little operation in a development environment can be critical. Is this an exaggeration? I'm not sure it is. Even if it is for this one thing, imagine this problem multiplied by two, or four. Not just one missing zero-cost operation, but two, or three. Suddenly with a more fluid environment, with just a few things made drastically better, development becomes less stilted and happens better.