Oh, well when it sleeps, it makes a sleep image, so when you wake it back up, your content should just pop back up. It might have to do with what it's trying to save before sleeping.
if the behavior is acting slower then usual you might need to run disk utility to see if there is anything wrong with the disk volume that would make it pause before fully sleeping.
Not sure how to resolve this specific issue. how old is your computer? what's the Disk Drive you have in it SSD or HDD?
it could mean your HDD is really full and it takes a while for things to be processed before completely sleeping.
It could also mean your HDD is failing but that's a shot in the dark.
It is almost brand new. It is a 27-inch, Late 2012 with a 2.9 Ghz Intel Core i5 with 16 GM 1600 MHz DDR3. The Hard Drive is as follows:
Available: 892.23 GB (892,233,703,424 bytes)
Capacity: 999.35 GB (999,345,127,424 bytes)
Mount Point: /
File System: Journaled HFS+
Ignore Ownership: No
BSD Name: disk0s2
Volume UUID: 2EEF42A1-440F-315A-9944-93842BBE23FE
Media Name: APPLE HDD ST1000DM003 Media
Medium Type: Rotational
Partition Map Type: GPT (GUID Partition Table)
S.M.A.R.T. Status: Verified
I have run Disk Utility and it says all is OK.