The first sign it is happening?? What are you looking for? IMHO, it IS happening now. There have been several shortages on goods and the prices don't seem to be stopping anyone from buying. What does that tell me? It tells me that people see the writing on the wall. It may not be a complete 'panic' situation now, but it is close. TP is still on the shelf, so 'panic' hasn't hit that level yet, but those (like many on this forum) can see it happening before our eyes and are buying whatever they can now. If you wait too long.....you won't be able to buy those 'big' ticket items b/c there won't be anything left. It's getting that way right now for many prouducts, especially with anything that has a computer chip or motor.
It may not be an overall 50% inflation rate currently, but I'm preparing now for just that. I'm spending cash like a drunken sailor.....just not on things a drunken sailor would spend on. I'm still investing in the market, b/c typically the market will keep pace with (and even beat) inflationary pressures. We are purchasing those things now that have been on our wish lists for a very long time. Unfortunately many of those purchases also come with a lot of work. So, we've been busy working and spending. When this year is in the rearview mirror, hopefully we can look back and be proud of how much we accomplished this year.
As far as energy prices, next month we will be meeting with someone to discuss geothermal options. That should save lots of money moving forward, even though the initial investment will take 4-6 years to pay for itself. I can live with that. That timetable may be even shorter if inflation really takes off.