In the thick of it phrase
If someone "is in the thick of it", he/she is fully involved in something, is in the middle of or very busy with several things
I really want to go camping with you guys this weekend, but I'm in the thick of it with my project.
Mary is really in the thick of it in order to forget about her break-up with Josh.
She was stressed out because she had been in the thick of it with her tight deadline.
It's too late for us to get out of here. We are in the thick of it.
This usage dates from the mid-1600s.
To say, or believe something or someone that seems completely crazy, delusional, or stupid
You spent 1000$ on a new pair of shoes! It is insanely crazy. You need your head examined.