I have had some major surgeries on my knee and the ACL was by far the easiest one! But as far as getting back it all depends on you, some people lay around for weeks after an ACL (seen it with my own eyes) others walk the next day, so just make sure that you follow all instructions and most protocols say 3 months before lifting again for an ACL but talk to your therapist because they have the most experience, plus (unlike your doctor) they will be able to see your day to day progress