No, you won’t always meet other travelers and yes, there are things (maybe museums in your case) that are more enjoyable when you’re sharing with someone.  You will probably be lonely at least once, but I think it’s easier to meet people when you’re alone. 

On the plus side, there are lots of advantages to solo travel.  No whining, no disagreements about what to see and do, no other ego to have to deal with.  Most importantly, there’s an I-can-do-anything feeling about traveling alone — it just feels great.  I think you’ll enjoy it, but if you’re not sure, plan a shorter trip or see if you can find somebody to travel with for part of the trip and do part of it solo.  Starting out solo with plans to meet someone, somewhere is ideal for me.     

Agree with Oldlady, at times it is lonely, but it is very empowering, and you do enjoy that I-can-do-whatever-I-want feeling. It is definitely a good thing to travel alone a few times in one’s life. As Oldlady says, you can always plan a shorter trip if you feel a bit doubtful, but that is indeed a busy time of year and there will be plenty of other backpackers out there.

I definitely believe in going alone from time to time too.  It is really easy to meet others.  My first solo trip I actually found myself hoping for more time alone more often than feeling lonely.