Back to work after holidays, exhausted after first day - is it just me?!

[Newnameshoos]

Pretty much what the title says!
I had a lovely holiday and wound down completely, no checking emails etc.
Back to work earlier this week, by the end of the day I was completely exhausted and in bed by 9pm! I don't remember being this exhausted going back before, wondering if it's because I stopped completely and had a proper rest, or my menopausal age?! Could it also be the heat?!
Please tell me it's not just me...

Did you come back to a ton of emails, things to catch up for n and do?
Are other colleagues now in leave so team is a bit short staffed?
If so I think that's what it is.
And by the end of the day it feels like you've never been away...
But heat and menopause probably make it worse!

Thanks @Dutchhouse14 I think it's coming back to a full appointment diary so my brain needing to work all day instead of pottering around cooking and gardening and stuff.