Should I start playing 1. d4

I've played 1. e4 since I started playing chess over 10 years ago.  I can probably count on my fingers and toes the number of times I have tried a d4 or Nf3 opening in those 10 years.  However, I think maybee it will help broaden my chess knowledge if I spend some time learning d4 positions from the white side.  Is this a useful way to learn more about the game?

I'd say yes.

Definitely! You will learn about the different plans in the queens pawn opening. U will also see different kind of pawn structures.

Maybe I should

Your sample size is too small to say anything definite about future outcomes. All opening moves have their peculiar disadvantages and countermeasures.

If you want to play 1.d4 go ahead and play it.

Yeah I know, was messing really. The d4s are all themed tournaments anyway.

I experimented with d4 after playing e4 for many years...  it definitely helped broaden my chess knowledge, but it also confuses me now because I never know which one to play :)

I usually play 1.e4, and at one point, I tried to play d4 to broaden my skills. It was the biggest disaster! I lost all my games and only won when I went back to e4 (and sprung a Smith-Morra Gambit on an unsuspecting victim!). If the transition goes smoothly, OK, but it just may not be your thing.

There's only one way to find out.

I posted this a while ago and I have since learned several d4 openings.  I am now quite happy playing against the Kings Indian, Nimzo Indian, Queens Gambit Declined and Accepted, Slav, Benoni, Old Indian, The dutch, and a few other openings,  I am glad that I took the time to learn d4 openings as it deffinitely brings a different flavor to chess games.  I'm not sure which I like better 1. e4, or 1. d4.  I'm going to continue with d4 for a while until I get the openings down a bit better than I am going to switch back to e4 and build a solid e4 repertoir like I have done with black.

That's a lot of switching.

Not switching, black gets to decide which opening to use for the most part.  I start d4, they play Nf6 it can go into a kings indian, nimzo, old indian, or queens indian.  They play d5 it goes into either a slav, a QGA, or QGD, if they play f5 than we are playing a dutch.  So when white plays d4 they have to know each of those openings.

Go for it, variety is the spice of life.

Interestingly 1. a3 is my best opening with 3 wins from 3 games.