Treading water

It's probably better to be treading water than to be struggling against the tide.
If I'm being really honest I'm doing better than treading water but I have to admit to an amount of frustration at the thought.
Are my expectations too high? Or am I putting too much pressure on myself to live a certain way, do certain things because I feel I should be?
I was told a fairly while back that if I enjoy doing something I should do it (of course we are talking within reason and the law) and not feel bad about it. Then I get the feeling I am missing out.
I look at some of my friends and the lives they lead and wonder whether I should strive to be more daring, a bit reckless or spontaneous instead of playing it safe. There's no such thing as safe though is there?
Should I be married, have children, a mortgage?
Life would certainly be a lot different, perhaps they would be great things to have in life and take my focus away from myself. That's probably the issue, where my focus is. Caution can be counter productive. Treading water can get exhausting.