Returning to work

I have finally negotiated the complicated path of requesting flexible working when my maternity leave ends at work.  For some inexplicable reason I had thought it would be a fairly straightforward process that would go something like this:

Me: "Can I come back part-time on the following days...?"
HR-Powers-That-be: "Yes/no"

Which would then result in me either happily toddling back to work under the agreed schedule, or unhappily plodding through endless job searches and rejections.

What it actually entails is this:

Me: "Can I come back part-time on the following days...?"
HR-Powers-That-be: "You need to fill out this convoluted form in detail.  We will not accept 'not applicable' as a response even if the question is totally irrelevant to your role."

I then return the form only to find they need more detail.  Like, a lot more detail.  We're talking a detailed account of Husband's shift pattern over the next 3 years, an immunoglobulin test result from Little Parasite, and a description of my proposed route to work including Google Map diagram.
The form is returned again and then I'm invited to a formal discussion with
HR-Powers-That-Be.  Expecting to have my work plan ripped a new one, I am somewhat surprised when essentially the only question they have is "may we phone you on your off days should we need to?"
Then, I wait a couple of weeks for the decision letter that will either see me sigh with relief, or sign up to numerous job seeker sites.

Fortunately, my request has been accepted so there is a lot less free-flying cortisol in the house.  Of course this has now freed up vital worry space in my brain to focus on the practicalities of returning to work.  I'm suddenly confronted with such pertinent questions as 'where the hell are my hair straighteners?' and 'do I even own clothes not stained with baby puke anymore?' This awakening to just how blinded I've become to my increasingly disheveled appearance warrants its own post (which I will no doubt neglect to write).

Apart from the obvious concern of forgetting how to actually do my job and dissolving into a pool of my own incompetency, I'm a little concerned that I may attempt to transfer my new found parenting skills into the workplace.  For example, when people become agitated during meetings I'm genuinely worried I may automatically start singing 'the wheels on the bus' to mollify them.

I still have a couple of months of maternity leave left before returning to work, and I fully intend to make the most of them with messy play, trips to the park, swimming and baby groups before the shock of a structured day hits us all.  Poor Little Parasite; kiss goodbye to your random 08:30 lie-ins.

Have you returned to work after a lengthy time off? How did you cope?  Did anything surprise you about the process?