Learning a programming language in amongst a full-time job (I'm a contractor, on a contract, so this comes out of my own time/pocket) and parenting my daughters (2 and 4) is a tricky process. Reading the book  on the bus to and from my client gives me 3 hours a week . Then I grab the odd 1/2 hour before and/or after work to test out the ideas via utop  or even using vim with merlin ).
It reminds me of Swift (which took a lot of inspiration from OCaml, apparently), Erlang (it's functional, uses guards/pattern-matching etc...) and Haskel (compiled, fast, functional, a focus on types etc... and there's a fair bit of mental adjustment needed).
Progress was slow and the The Go Programming Language  book started to look more appealing. Go is a simple language, it prioritises clear simple building blocks and an idiomatic style. It should appeal, and it does, but reading TGPL wasn't drawing me in. While Go is practical and powerful, the challenge of OCaml was greater. OCaml's extra complexity has been designed for a purpose and it doesn't pander to convention.
I have the impression that persevering will yield something worthwhile.
Hours of OCaml reading time:
(* define a recursive function * recurse a list and check each item is the same *) let rec same a_list = match a_list with |  | [_] -> true | hd1 :: hd2 :: tl -> if hd1 <> hd2 then false else same (hd2 :: tl);; (* call same * with some equivalent values * 3 days * 2 trips * each trip 1/2 hour *) same [ (3. *. 2. *. 0.5); (( *. ) 3. (( *. ) 2. 0.5)); 3. ];; (* returns true *)