Are you Bi ??

I breathe bilaterally because the habit was beaten into me by my swim coaches when I was a kid.

By the way, the flaw in your first attempt was you left out the (breathe right) step. 

That's an important statement.  The ability to breathe competently on both sides is more important IMO than the ability to breathe bilaterally.

at the pool, easy to moderate 60% right, 40% left. hard efforts, 80-85% right.

races - 90% + on the right, even in HIM swim. not trying to force the strict bilateral yet. stroke is stil way better breathing to the right. i tend to skip a breath rather than bilateral sometimes.

my wife said she saw someone with a snorkel in my last race. you could try that

The best way to breath bilateral is to stop breathing IN while switching from left to right.

If you are strugling with feeling like you can not get enough air try taking smaller breaths, then make sure you breath out more than you breath in.  Make sure that most of you out is while you are under, then blow the rest out as you finish your roll to breath, this will help get the loose water away from your mouth and make the in breath feel a little less labored.  Helps with rythem if laboring is not a factor.

This ^^^ for me also!

Great input.

So I am gathering that I do not HAVE to swim bilateral, but it is a good skill to have.

Makes sense. What would happen to me in a OWS if the waves would always come from my breathing side. Guess thats where the fish option would come in handy.

My swim coach has been hammering bilateral however we do work on lateral left and or right side...since it is best to have the ability to go with whatever the conditions ie: wave chop and environment ie: another swimmer right beside you ,will dictate how I breath.

I found in my last race , a HIM...once I got into the open water I was doing a 2/3/2 which was practiced as well...seems to be an efficient means of breathing and a good overall balance....for me.

This.  I breathe when I need to - and that varies depending on conditions and my effort.  I prefer to breathe bilaterally, but that's not always the most effective option.

I started out only breathing to my left, but now swim 99% of the time bilaterally.  It's become 100% natural, and it feels odd when I only breathe to one side.  I was like you originally and could not breathe on my opposite side.

Couple of reasons for me:  1)  OWS - I can swim better on either side as needed.  2)  My balance is better in the water (may have become better either way).  3)  I swim straighter - for whatever reason when I breathe to one side I have a tendency to drift that direction when there is no black line to keep me straight.

I started out breathing only right, then had lessons and started breathing bi.

Now in the pool, I'll do my sets where I breath only left.

OW I usually only breath right.

I went bilateral for two reasons:

(1) It allowed me to vary my breathing interval. I tend to go every third stroke, but when the effort goes up, I go two, three, two, three, etc.

(2) It allows me to breath on whatever side I need for sun/waves/whatever. It's come in very handy a couple times this season.

I breathe on my right side 99% of the time.  I can breathe on the left side just as easy, but I formed a habit.  The only time I breathe on my left is if i am trying to avoid looking directly into the sun, if i want to see something on my left, or if I have a competitor a few inches away from me on my right side.  Nothing is creepier than turning to breathe and see a competitor turn and breathe facing you when they are just inches away. 

It is good to know how to breathe on both sides, but it is not necessary to bilateral breathe all the time

I swim bilateral because otherwise my neck begins to hurt.

But bilateral for me isn't always every 3rd stroke.  Sometimes I breathe to the right one length, then the left the next length.  I usually breathe every 3rd stroke on endurance sets.

Andi