Hypo one night, hyper the next?!

Diabetes is a fickle disease - you can be doing everything exactly the same two days in a row and get vastly different results. I don't know how long you've been diagnosed and in treatment but it's very possible to be having honeymoon swings there too.

Do you log everything? That includes the food, any exercise you did during the day, whether you slept well or poorly etc. next to your glucose values. If you can get an understanding of what your body does with various activities and food, you can estimate what you need to do to reduce spikes as much as possible.

Do you wait 10-20 minutes to eat after you take your bolus?

Try not to get too concerned about random type swings, having a low can cause a yo yo effect and create a following high even if you do not over treat the low. If you then over correct the high it can cause the yo yo effect to be worse or last longer.

As @DaftThoughts has already mentioned there are times when you look back at your records/memory and BG changes make full sense to you based upon what you ate, when you took your insulin and the amount taken, plus your health at the time, also the level of exercise and lastly the BG you had before your meal.

Other times your BG just makes no sense at all and you cannot work out any reasoning, its best not to get annoyed trying to resolve the cause of these, just try forget about them and carry on with your life. TBH this was the hardest part of diabetes that I found I had to come to terms with.