The phrase "deep end" refers to being in a difficult or challenging situation or experiencing intense emotions. It can also mean being thrown into a task or activity without any preparation or guidance. Full definition
The staff, working as a unit, builds the assessments that drive instruction to deeper ends for all students and a new learning climate emerges. (ilc21.org)
Most of the older pools only have 9 - foot deep ends, and we had to remove the boards. (articles.chicagotribune.com)
Our own Deep End Editor has wondered whether we should be a little less exercised about the aid budget and a little more exercised by much larger taxpayer subsidies of the banking sector. (conservativehome.blogs.com)